Chapter 3C Assignment Sheet

Transcription

1 Stat Tech Chapter 3C Assignment Sheet Percentiles Day 1 1. The reaction time to a stimulus for a certain test has a mean of 2.5 seconds and a standard deviation of 0.3 seconds. Find the corresponding z-score for each reaction. a. 2.7 b. 3.9 c. 2.8 d. 3.1 e Which of these exam grades has a better relative position. (Make sure you give the z-score also) a. A grade of 43 on a test with a mean of 40 and a standard deviation of 3 b. A grade of 75 on a test with a mean of 72 and a standard deviation of 5 3. Given the following: a. Find the Percentile Rank of 16 b. Find the Percentile Rank of 20 c. Find the Percentile Rank of 5 d. Find the Percentile Rank 12

2 Percentiles Day 2 1. An aptitude test has a mean of 220 and a standard deviation of 10. Find the corresponding z score for each of the following exam scores. a. 200 b. 232 c. 218 d. 212 e A student scores 50 on a math test that has a mean of 54 and a standard deviation of 3, and she scores 70 on a history test with a mean of 75 and a standard deviation of 2. What is the z score for each test and which test did she perform better? 3. Given the following set of weights: a. Find the percentile rank for a weight of 86 pounds b. Find the percentile rank for a weight of 88 pounds c. Find the percentile rank for a weight of 82 pounds d. What value corresponds to P 30 e. What value corresponds to P 80 f. What value corresponds to Q 3 4. Given the following set of test scores: a. Find the percentile rank for a score of 42 b. Find the percentile rank for a score of 49 c. Find the percentile rank for a score of 28 d. What value corresponds to the 60 th percentile e. What value corresponds to the first quartile f. What value corresponds to the 15 th percentile

3 Outliers / Box Plot 1. Check the following for outliers: a. 321, 343, 350, 327, 200 b. 88, 72, 97, 84, 86, 85, 100 c. 53, 62, 78, 94, 96, 99, 103

4 2. The following data are the number of calculators sold during a week Give the 5-Number Summary Construct a box plot and summarize 3. The number of broadway plays over the past several years Give the 5-Number Summary Construct a box plot and summarize

5 Ch. 3C Extra Practice 1. The lengths of service (in years) of the Chief Justices of the Supreme Court are: a. What is the percentile rank for 5 b. What is the percentile rank for 11 c. What is the percentile rank for 16 d. What is the percentile rank for 22 e. Find Q 1 f. Find Q 2 g. Find Q 3 h. Find P 65 i. Find P 95 j. Find the value that corresponds to the 35 th Percentile k. Find the value that corresponds to the 15 th Percentile l. Find IQR m. Give the 5-Number Summary n. Construct a Box-and-Whisker Plot & Summarize 2. The following data are the number of burglaries reported for a specific year for nine Western Pennsylvania universities a. What is the percentile rank for 1 b. What is the percentile rank for 3 c. What is the percentile rank for 30 d. What is the percentile rank for 18 e. Find Q 1 f. Find Q 2 g. Find Q 3 h. Find P 65

6 i. Find P 95 j. Find the value that corresponds to the 35 th Percentile k. Find the value that corresponds to the 15 th Percentile l. Find IQR m. Give the 5-Number Summary n. Construct a Box-and-Whisker Plot & Summarize 3. Check the following for outliers: a b c

7 Chapter 3C Review 1. The average number of newspapers for sale in an airport newsstand is 12 and the standard deviation is 4. If a newsstand has 9 newspapers, what is their z-score? 2. An average delivery charge for a refrigerator is $32 and the standard deviation is 4. If the delivery charge is $45, what is the z-score? 3. Which of these exam grades has a better relative position? A: A grade of 37 on a test with a mean of 42 and a standard deviation of 5. B: A grade of 72 on a test with a mean of 80 and a standard deviation of What if these test grades has a better relative position? Science: A grade of 76 with a mean of 75 and a standard deviation of 2. English: A grade of 80 with a mean of 76 and a standard deviation of The number of credits in business courses that eight job applicants took is: a. What is the percentile rank for 15 b. Find Q 1 c. Find Q 2 d. Find Q 3 e. Find the value that corresponds to the 30 th percentile f. Calculate IQR g. List the 5-Number Summary h. Construct a box-and-whisker plot & Summarize

8 6. The number of previous jobs held by each of six applicants is shown: a. What is the percentile rank for 8 b. Find Q 1 c. Find Q 2 d. Find Q 3 e. Find the value that corresponds to the 65 th percentile f. Calculate IQR g. List the 5-Number Summary h. Construct a box-and-whisker plot & Summarize 7. Mathematically check the following for outliers: 3, 7, 9, 6, 8, 10, 14, 16, 20, Mathematically check the following for outliers: 506, 511, 517, 514, 400, According to the Empirical Rule, when a distribution is normally distributed, the following is true: Approximately % of the data values will fall within 1 standard deviation of the mean. Approximately % of the data values will fall within 2 standard deviations of the mean. Approximately % of the data values will fall within 3 standard deviations of the mean.