Download Statistics Problems and Solutions and more Study notes Statistics in PDF only on Docsity! 1. Given the following information, what is the standard deviation? x = 22 2x = 132 n = 5 2. Given the following values, what is the 33rd percentile? X: 1 3 5 2 8 3. If Q1 = 25, median = 84.0, and P75 = 100. What is the Interquartile Range and how much of the data does it cover (or span) respectively? 4. Given the following information: x = 22 (x2) = 132 y = 17 (y2)= 89 (xy) = 61 n = 5 Find the correlation coefficient 5. The average age in college is 20 years old with a standard deviation of 1.2 years. About how many people would there be between 18.8 and 21.2 years old? 6. Given the information from #4 What is a and b from the regression equation respectively? 7. The marks on a statistics test are normally distributed with a mean of 62 and a variance of 225. If the instructor wishes to assign A's or higher to the top 20% of the students in the class, what mark is required to get an A? 8. X is normally distributed with a mean of 100 and standard deviation of 20. What is the probability that X is greater than 69? 9. 5% of the students enrolled in this course generally fail. Given a sample of size 40, how many are expected to pass? 10. Given that A and B are independent events, with P(A) = .40 and P(B)=.30, what is the probability of their union? 11. If P(A|B) = .25, P(A)=.6, and P(B)=.25, what is P(B|A)? 12. There are 15 marbles in a bag: 5 green, 3 black, 4 red, and 3 blue. What is the probability that if 2 marbles are selected without replacement, both are blue? 13. X is a binomial variable where n=5 and p=0.4. What is P(at least 1)? 14. X is binomial variable where n=22 and p=.30. What is the standard deviation? 15. 90% of people dislike statistics. In a random sample of 12 people, what is the probability that 9 people will dislike statistics? 16. Two dice are rolled simultaneously. What is the probability that their sum is an odd number? 17. Suppose 250 students had a sample mean of 20 and = 5. Give the 95% confidence interval for the population mean. 18. A sample of 50 cans of cola was analyzed for amount of caffeine. The results yielded x = 57.8 and standard deviation of 10. Test the following Ho: = 60 Ha: > 60 With a significance level of 0.10, what is the correct decision? 19. H0: = 10 HA: > 10 Given that = 2, and that a sample of 64 gave a sample mean of 10.51. What is the p-value? a
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