STATS 302 Practice Final Exam Questions and Answers

STATS 302 Practice Final Exam Questions and Answers Anna Grace is conducting a survey of Texas A&M students. She asks them their age, gender, current GPA, major, current number of credit hours, high school GPAs, and number of days of class they missed in the last month. What kind of variable is major? - ANSWER-qualitative Taylor Swift wants to know the proportion of her fans who listened to her new single ME! within the first hour of it being released. In order to estimate this, she takes a sample of 150 of her fans and asks them if they listened to the song in this time period. Of the 150 fans, 135 of them (90%) responded that they did listen to the song during this time period. What is the parameter and what is its value? - ANSWER- The parameter is the proportion of all Taylor Swift fans who listened to ME! within the first hour after it was released, which is unknown. In which of the following study designs would you generally know the value of the parameter? - ANSWER-Census A researcher wants to determine if a new flu vaccine protects from the flu better than the current vaccine. He has 100 subjects for his study. He believes that sex will affect how well the vaccine works, so within these 100 subjects, splits them up into males (48 subjects) and females (52 subjects). Within each sex, he randomly assigns half of the subjects to get the new flu vaccine and the other half to get the current flu vaccine. What type of study design is this? - ANSWER-Experimental Study: Block Design Consider the following set of data: 2, 3, 4. What is the standard deviation? - ANSWER-1.00 The boxplot below shows the distribution of heights of 16 undergraduate statistics students. Using the boxplot, approximately how many students are 64 inches or taller? - ANSWER-12 Copyright © KAYLIN 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED FIRST PUBLISH NOVEMBER, 2024 Copyright ©Stuvia International BV Page 2/10 The average on a history exam (out of 100 points) was 85, with a standard deviation of 15. What shape would you expect the distribution of grades to take? - ANSWER-Left Skewed Anna teaches a small class of 14 students. She recently gave them an exam (out of 100 points). The scores on the exam were: 0, 15, 58, 75, 78, 82, 84, 84, 89, 91, 94, 98, 100, and 100. How many of the scores are potential outliers? - ANSWER-2 One common disease among pediatric patients is streptoccal pharyngitis (strep throat). If a pediatric patient comes into the pediatricians feeling ill, there is a 26% chance that they have strep throat. A doctor sees 7 pediatric patients on a particular day (assume these patients are independent). Consider the random variable as a binomial random variable such that X = number of pediatric patients with strep throat. What is the chance that at least one of them has strep throat? - ANSWER-0.878 Heights of adult American women are normally distributed with a mean of 65 inches and a standard deviation of 3.5 inches. Taylor is a 28 year old American woman. Her doctor tells her that her height is below average but less than one standard deviation away from the mean. Which of the following could potentially be the z-score of her height - ANSWER-None of the above A health study reported that, in one country, systolic blood pressure readings have a mean of 122 and a standard deviation of 15. A reading above 140 is considered to be high blood pressure. If the systolic blood pressure in that country has a normal distribution, using the z-table, what proportion of the population suffers from high blood pressure? - ANSWER-0.1151 An index that is a standardized measure used in observing infants over time is approximately normal with a mean of 96 and a standard deviation of 10. What index score is less than 33% of the population index scores? - ANSWER-100.40 Copyright © KAYLIN 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED FIRST PUBLISH NOVEMBER, 2024 Copyright ©Stuvia International BV Page 3/10 Sarah wants to determine the average height of all students at Wittenberg University. In which of the following scenarios would Sarah be looking at the sampling distribution? - ANSWER-Sarah and her 20 classmates each survey 40 students at Wittenberg University and ask them their height. Each person calculates the average of their sample and Sarah looks at all these averages. The lengths of human pregnancies from conception to birth varies according to a distribution that is approximately Normal with a mean of 266 days and a standard deviation of 16 days. A study enrolls a random sample of 25 pregnant women. Assuming all appropriate conditions are met, what is the probability that the average pregnancy length of the women in the study is more than 268 days? - ANSWER-0.2643 Which of the following is true about sampling distributions? - ANSWER-Sampling distributions get closer to normality as the sample size increases. Which of the following would be the best interpretation of 99% confidence? - ANSWER-If we were to take 100 samples, then approximately 99 would contai