TEST 1 REVIEW (STA 2023)

Provide an appropriate response. 9) The scores on a recent statistics test are given in the frequency distribution below. Construct the corresponding relative frequency distribution. Round relative frequencies to the nearest hundredth of a percent if necessary. Scores Frequency 0 - 60 3 61 - 70 10 71 - 80 11 81 - 90 4 91 - 100 1 9) A) Scores Relative Frequency 0 - 60 15.5% 61 - 70 22.1% 71 - 80 31.3% 81 - 90 16.2% 91 - 100 14.9% B) Scores Relative Frequency 0 - 60 0.21% 61 - 70 0.24% 71 - 80 0.55% 81 - 90 0.03% 91 - 100 - 0.03% C) Scores Relative Frequency 0 - 60 12.5% 61 - 70 20.1% 71 - 80 37.3% 81 - 90 15.2% 91 - 100 14.9% D) Scores Relative Frequency 0 - 60 10.34% 61 - 70 34.48% 71 - 80 37.93% 81 - 90 13.79% 91 - 100 3.45% 10) A nurse measured the blood pressure of each person who visited her clinic. Following is a relative - frequency histogram for the systolic blood pressure readings for those people aged between 25 and 40. The blood pressure readings were given to the nearest whole number. Approximately what percentage of the people aged 25 - 40 had a systolic blood pressure reading between 110 and 119 inclusive? 10) A) 3.5% B) 30% C) 0.35% D) 35% 3

Find the standard deviation for the given sample data. Round your answer to one more decimal place than is present in the original data. 17) 22.6 16.1 36.1 36.0 23.8 20.3 17) A) 3999.0 B) 4347.7 C) 36.1 D) 8.35 Find the coefficient of variation for each of the two sets of data, then compare the variation. Round results to one decimal place. 18) The customer service department of a phone company is experimenting with two different systems. On Monday they try the first system which is based on an automated menu system. On Tuesday they try the second system in which each caller is immediately connected with a live agent. A quality control manager selects a sample of seven calls each day. He records the time for each customer to have his or her question answered. The times (in minutes) are listed below. Automated Menu: 11.7 7.4 3.9 2.9 9.2 6.3 5.5 Live agent: 6.2 2.9 4.4 4.1 3.4 5.2 3.7 18) A) Automated Menu: 25.2% Live agent: 41.5% There is substantially more variation in the times for the live agent. B) Automated Menu: 47.1% Live agent: 27.3% There is substantially more variation in the times for the automated menu system. C) Automated Menu: 45.4% Live agent: 26.3% There is substantially more variation in the times for the automated menu system. D) Automated Menu: 48.8% Live agent: 28.3% There is substantially more variation in the times for the automated menu system. Use the empirical rule to solve the problem. 19) The amount of Jen's monthly phone bill is normally distributed with a mean of $55 and a standard deviation of $12. What percentage of her phone bills are between $19 and $91? 19) A) 95% B) 99.99% C) 68% D) 99.7% Find the z - score corresponding to the given value and use the z - score to determine whether the value is unusual. Consider a score to be unusual if its z - score is less than - 2.00 or greater than 2.00. Round the z - score to the nearest tenth if necessary. 20) A test score of 48.4 on a test having a mean of 66 and a standard deviation of 11. 20) A) 1.6; not unusual B) - 1.6; not unusual C) - 1.6; unusual D) - 17.6; unusual Determine which score corresponds to the higher relative position. 21) Which score has the highest relative position: a score of 5.6 on a test for which x = 3.9 and s = 1.2 or a score of 386.8 on a test for which x = 358 and s = 48? 21) A) Both scores have the same relative position. B) A score of 5.6 C) A score of 386.8 Find the percentile for the data value. 22) Data set: 12 18 42 24 12 30 54 54 66 18 18 54 36 6 54 Data value: 42 22) A) 60 B) 70 C) 52 D) 35 6