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St Petersburg College Florida
Statistics (Stat 2023) Midterm
Exam
Course Title and Number: Statistics (Stat 2023) Exam Title: [Insert Exam Title] Exam Date: [Insert Exam Date] Instructor: [Insert Instructor’s Name] Student Name: [Insert Student’s Name] Student ID: [Insert Student ID]
Midterm Examination
180 minutes
Instructions:
**1. Read each question carefully.
- Answer all questions.
- Use the provided answer sheet to mark your** **responses.
- Ensure all answers are final before submitting the** exam.
Good Luck!
. The type of marsh found growing in a reserve. - Answer>> Qualitative The length of a super bowl commercial - Answer>> Quantitative The elevation of an airport. Is - Answer>> quantitative The blood type of a patient in the emergency room is - Answer>> qualitative The number of oranges contained in a 5-pound bag is - Answer>> Discrete The temperature of a freshly brewed cup of coffee. Is - Answer>> Continuous The wind speed recorded at Tampa International Airport is - Answer>> Contonuous The number of oranges contained in a 5-pound bag is - Answer>> Discrete The number of hot dogs sold during a game by a Tampa Bay Ray hot dog vendor. Is - Answer>> Discrete Identify the Population. A study is conducted to determine the average amount of money full-time SPC students spend on textbooks per semester. A sample of 100 full-time SPC students is taken by dividing the student body into freshmen, sophomores, juniors and seniors, and then selecting a proportional number from each class. Each student in the
The following histogram represents the distribution of Heights of 31 Black Cherry Trees. Approximately what percent of the Cherry trees are greater than 80 feet tall? - Answer>> 23% Use the graphical display to answer the question. The following box-plot contains the cholesterol levels of 100 patients. How many of the patients had cholesterol levels between 180 and 265? - Answer>> 75 Use the graphical display to answer the question. The following box-plot contains the cholesterol levels of 100 patients. How many of the patients had cholesterol levels between 154 and 211? 75 - Answer>> 75 Use the graphical display to answer the question. The following box-plot contains the cholesterol levels of 100 patients. How many of the patients had cholesterol levels between 211 and 265? - Answer>> Use the graphical display to answer the question. The following box-plot contains the cholesterol levels of 100 patients. How many of the patients had cholesterol levels between 180 and 211? - Answer>> Identify the overall shape of the distribution and determine whether the mean or the median would provide a better measure of center. Shown below is a histogram for the length of 50 iTunes songs - Answer>> Skew right, the median would provide a better measure of the center.
- Answer>> Identify the overall shape of the distribution and determine whether the mean or the median would provide a better measure of center. Shown below is a histogram for the height
of 51 students. - Answer>> Skew left, the median would provide a better measure of center Find the mean. An academic adviser recorded the number of classes six randomly selected students were enrolled in. 4 3 1 2 3 5 R - Answer>> the mean is 3 Find the mean. The following data set contains 6 quiz scores coming from a class of 30 students. 13 8 13 8 4 8. The mean is 9 - Answer>> The mean is 9 Find the median. The following data set contains 6 quiz scores from a class of 30 students. 13 8 13 8 4 8 - Answer>> The median is 8 Find the median. An academic adviser recorded the number of classes six randomly selected students were enrolled in. 4 4 1 2 3 5. The median is 3.5 - Answer>> The median is 3. Find the mode. An academic adviser recorded the number of classes six randomly selected students were enrolled in. 4 4 1 2 3 5 - Answer>> The mode is 4 Determine the range. The following data set contains 6 quiz scores from a class of 30 students .13 8 13 8 4 8, the range is 9
- Answer>> The range is 9 Find the range. An academic adviser recorded the number of classes six randomly selected students were enrolled in. 4 4 1 2 3 5. - Answer>> The range is 4 Find the sample standard deviation. The following data set contains 7 quiz scores from a class of 30 students. 13 8 13 8 4 8 9. - Answer>> The standard deviation is 3. Find the sample standard deviation. An academic adviser recorded the number of classes six randomly selected students
what percent of loans have an interest rate that is between 3% and 15%? 95 % - Answer>> 95% In the United States, the distribution of a female's height has a mean of 64 inches with a standard deviation of 3 inches. How many standard deviations from the mean is Sally, who is 65 inches tall? - Answer>> 0.33 standard deviations above the mean Determine the number of standard deviations from the mean (z- score).In the United States, the distribution of a female's height has a mean of 64 inches with a standard deviation of 3 inches. How many standard deviations from the mean is Sally, who is 69 inches tall? - Answer>> 1.67 standard deviations above the mean Determine the number of standard deviations from the mean (z- score). In the United States, the distribution of a male's height has a mean of 69 inches with a standard deviation of 3 inches. How many standard deviations from the mean is John Doe, who is 65 inches tall? - Answer>> 1.33 standard deviations below the mean Determine the number of standard deviations from the mean (z- score). In the United States, the distribution of a male's height has a mean of 69 inches with a standard deviation of 3 inches. How many standard deviations from the mean is John Doe, who is 67 inches tall? - Answer>> 0.67 standard deviations below the mean. The average percentage of correct responses on last semester's Midterm was 78%. What can be said about a particular student's percentage correct if their z-score is positive? - Answer>> The student scored above 78% The average percentage of correct responses on last semester's Midterm was 78%. What can be said about a
particular student's percentage correct if their z-score is negative? - Answer>> The student scored below 78% Scores on the verbal reasoning portion of the GRE have a mean of 150 and a standard deviation of 8. What can be said about a particular student's performance if their z-score is negative two? The student scored a 142. - Answer>> The student scored a 142 Use z-scores to make the following comparison. A high school student took two college entrance exams, scoring 1070 on the SAT and 25 on the ACT. Suppose that SAT scores have a mean of 950 and a standard deviation of 155 while the ACT scores have a mean of 22 and a standard deviation of Assuming the performance on both tests follows a normal distribution, determine which test the student did better on? - Answer>> SAT Use z-scores to make the following comparison. A high school student took two college entrance exams, scoring 1110 on the SAT and 27 on the ACT. Suppose that SAT scores have a mean of 950 and a standard deviation of 130 while the ACT scores have a mean of 22 and a standard deviation of Assuming the performance on both tests follows a normal distribution, determine which test the student did better on?. - Answer>> ACT Use z-scores to make the following comparison.. Assume that male and female heights are normally distributed and that the average height for a male is 71 inches with a standard deviation of 4.3 inches and that the average height for a female is 65 inches with a standard deviation of 3.5 inches.Determine whether a male who is 82 inches tall or a female who is 77 inches tall is comparably taller after the variable gender has been accounted for. FEMALE - Answer>> FEMALE
that a student does not make the honor roll? - Answer>>
Find the indicated probability. A hotel has 20 rooms on the first floor, 60 rooms on the second floor, 40 rooms on the third floor, and 20 rooms on the fourth floor. If a hotel room is assigned at random, what is the probability of getting a room on an odd floor? - Answer>> if is and odd floor is 3/ if is even is 4/ Find the indicated probability. A large basket of fruit contains 3 oranges, 2 apples and 5 bananas. If a piece of fruit is chosen at random, what is the probability of getting an orange or a banana? - Answer>> 4/ Find the Indicated Probability. A survey of 150 people revealed that 115 people like ketchup on their hot dogs, 85 people like mustard on their hot dogs and 60 people like both. What proportion of those surveyed like ketchup or mustard on their hot dog? - Answer>> 140/ Find the Indicated ProbabilityIn. The US, 37% of household have dogs, 30% of households have cats, and 7% of households have both cats and dogs.What percentage of US households have a cat or a dog? - Answer>> 60%
- Answer>> Find the indicated probability.Recent statistics show that 62% of people wash their hands after using the restroom. If you shake hands with three random people, what is the probability that all of them washed their hands after previously using the restroom? - Answer>> 0. Find the indicated probability. Sixty percent of clowns aren't funny. If you randomly encounter three different clowns, what is
the probability that none of them are funny? - Answer>>
A baseball park has determined that the number of people contained in each vehicle parked in one of their lots has following distribution. What is the probability that more than 4 people arrive in a vehicle? - Answer>> 0. All human blood can be "ABO" typed as belonging to one of A, B, O, or AB types. The actual distribution varies slightly among different groups of people, but for a randomly chosen person from North America, the following are the approximate probabilities: What is the probability that a randomly chosen person from North America has AB type blood? - Answer>>
Find the indicated probability. On a particular night, a baseball stadium sells 60% of its seats, and of those, 15% do not end up showing up to the game. Assuming everyone present is sitting in a seat, what percentage of seats in the stadium are empty? - Answer>> 49% Find the indicated probability.At a certain college 40% of the students are male, and of those, 15% smoke cigarettes. What is the percentage of the student body who are male smokers? - Answer>> 6% Find the indicated probability. In general, after a group makes a reservation at a restaurant, they do not show up 20% of the time. If a restaurant has 8 reservations for the evening, what is the probability that exactly two do not show up? - Answer>> IF exactly two do not show up is 0. IF more than two do not show upis 0. Find the indicated probability.In general, the probability that a blood donor has Type A blood is 0.40.Consider 8 randomly chosen blood donors, what is the probability that exactly half of
Fahrenheit? 0.13 - Answer>> If is greater than 99 degrees fahrenheit is 0. If the temperature is between 98-99 is 0. Identify the z-score corresponding to the indicated percentile. For the standard normal curve, identify the z-score that corresponds to the 20th percentile. -0.84 - Answer>> 20th percentile is -0. 67th percentile is 33th percentile is -0. 80th percentile is 0. Identify the score corresponding to the indicated percentile. The length of human pregnancies (with no complications) from conception to birth varies according to a normal distribution with mean 260 days and standard deviation 10. Only ten-percent of pregnancy lengths are less than what value? - Answer>> 247 days Identify the score corresponding to the indicated percentile. Cardiac pacemaker batteries will stop working if they are not properly calibrated and charged. Suppose that the length of time a battery operates follows a normal distribution with mean 25.0 days and standard deviation 2.0 days. At what point will 1% of the batteries will fail? - Answer>> 20.34 days Identify the data value corresponding to the indicated percentile. The amount of sleep an adult gets per day is normally distributed with a mean of 7 hours and a standard deviation of 1.5 hours. Five-percent of adults sleep more than how many hours per day? 9.5 hours - Answer>> 9.5 hours Identify the data value corresponding to the indicated percentile. The heights of women are normally distributed with a mean of 65 inches and a standard deviation of 2.5 inches. The tallest 10% of females are taller than what height. - Answer>> 68.2 inches
Select the most appropriate response. One normal distribution has a mean of 34 and a standard deviation of 2 and another normal distribution has a mean of 23 with a standard deviation of 7. Which distribution is more variable? - Answer>> The second normal distribution Select the most appropriate response.A company maintains a fleet of vehicles that consist of both cars and trucks. The miles per gallon realized in the cars follows a normal distribution with mean of 30 and a standard deviation of 2 while the miles per gallon realized in the trucks follows a normal distribution with mean of 17 with a standard deviation of 3. Which distribution is more variable? - Answer>> The mpg for the trucks Find the indicated probability. The age of professors at a certain university is normally distributed with an average of 45. years and a standard deviation of 6.0 years. If 16 professors are chosen at random for a committee, find the probability that the average age of those professors is less than 42.0 years. - Answer>> 0. Find the indicated probability.The age of professors at a certain university is normally distributed with an average of 45.0 years and a standard deviation of 6.0 years. If 16 professors are chosen at random for a committee, find the probability that the average age of those professors is greater than 42.0 years. - Answer>> 0. Find the indicated probability. Let X be the number showing on a fair six-sided die. The distribution of X has mean 3.5 and standard deviation 1.71. If a six-sided die is rolled 30 times, what is the probability that the average of all 30 rolls is less than 3? - Answer>> 0. Use z-scores to make the following comparison. Assume that male and female heights are normally distributed and that the
you happen to have data available on the following groups of children. Which would be the best sample for your study? a. Your own child. b. Four of your family members, two of which have been vaccinated and also have autism, and two of which have not been vaccinated and do not have autism. c. A set of 1000 vaccinated European children, randomly chosen by phone number. d. A set of 1000 European children, both vaccinated and unvaccinated, randomly chosen by phone number. - Answer>> d. A set of 1000 European children, both vaccinated and unvaccinated, randomly chosen by phone number. 'Children can learn a second language faster before the age of 7'. Is this statement: a. A one-tailed hypothesis b. A non-scientific statement c. A two-tailed hypothesis d. A null hypothesis - Answer>> a. A one-tailed hypothesis 'Children can learn a second language differently before the age of 7 than after.' Is this statement: a. A non-scientific statement b. A two-tailed hypothesis c. A one-tailed hypothesis d. A null hypothesis - Answer>> b. A two-tailed hypothesis There are basically two types of statistics - descriptive and inferential. Which of the following sentences are true about descriptive statistics? a. Descriptive statistics describe the data. b. Descriptive statistics enable you to draw inferences about your data, for example does one variable predict another variable?
c. Descriptive statistics enable you to make decisions about your data, for example, is one group mean significantly different from the population mean? d. All of the above. - Answer>> a. Descriptive statistics describe the data The aim of experimental research is to a. Prevent a phenomenon b. Cause a phenomenon c. Be a phenomenon d. Investigate what caused a phenomenon - Answer>> d. Investigate what caused a phenomenon In experiments the independent variable is manipulated to determine: a. Effects of certain stimuli b. Effects on the individual participants c. Relation to other variables d. Effect on the dependent variable - Answer>> d. Effect on the dependent variable Which of the following statements would be considered a two- tailed hypothesis? a. It is clear that there is a relationship between a healthy balanced diet and feelings of well-being. b. The use of antibiotics will not impact the progression of a viral infection. c. A female doctor will be more empathetic than her male counterpart. d. As rates of immunization for measles increase, the incidence of measles will decrease. - Answer>> a. It is clear that there is a relationship between a healthy balanced diet and feelings of well-being. Which of these hypotheses is a one-tailed research hypothesis? a. A > B.
Which of these hypotheses is a nondirectional alternative hypothesis? A = B. A > B or B > A. B > A. A > B. - Answer>> A > B or B > A. A two-tailed test is considered a: Uni-directional test Directional test Non-directional test Bi-directional test - Answer>> Non-directional test Which of the following would be classed as a two-tailed hypothesis? a. The training intervention will result in a significant increase in aerobic capacity. b. The training intervention will result in a decrease in aerobic capacity. c. The training intervention will result in an increase in aerobic capacity. d. The training intervention will evoke a change in aerobic capacity. - Answer>> d. The training intervention will evoke a change in aerobic capacity. Type 1 Error - Answer>> rejecting a null hypothesis when it is in fact true Type 2 Error - Answer>> failing to reject null hypothesis when it is in fact false What is the conventional level of probability that is often accepted when conducting statistical tests? . . .
.001 - Answer>>. Which of the following descriptions best describes the statistical power? a. Accept the null hypothesis when the null hypothesis is false. b. Accept the null hypothesis when the null hypothesis is true. c. Reject the null hypothesis, when the null hypothesis is false. d. Reject the null hypothesis when the null hypothesis is true. - Answer>> c. Reject the null hypothesis, when the null hypothesis is false. What is a significance level? - Answer>> A pre-set level of probability at which it will be accepted that results are due to chance or not. Usually =. test statistic - Answer>> number that measures outcome of experiment p value - Answer>> probability of obtaining a result as extreme or more extreme than your result due to chance alone small p value - Answer>> more significant than larger p values power (of a statistical stat) - Answer>> chance of rejecting null when null is false instrument - Answer>> a device use to take measurements reliability - Answer>> does the instrument work every time? validity - Answer>> does the instrument measure what it's supposed to measure Testing reliability of Instrument: Test/retest - Answer>> correlate test scores with retest scores. Testing reliability
