Exam 6: Putting Statistics to Work

Find the median for the given sample data. -The number of vehicles passing through a bank drive-up line during each 15-minute period was recorded. The results are shown below. Find the median number of vehicles going through the line In a fifteen-minute period. 20 22 20 23 23 20 25 22 30 26 26 24 19 26 20 15 10 22 22 22

A hypothesis test is to be performed. State the null and alternative hypotheses. -In a clinical study of an arthritis medication, $28 \%$ of those taking the placebo reported improvement. The manufacturer of the medication claims that among those taking the medication, the proportion reporting improvement will be higher than this.

Provide an appropriate response. -We want to compare two different groups of students, students taking Composition 1 in a traditional lecture format and students taking Composition 1 in a distance learning format. We know that the mean score on the research paper is 85 for both groups. What additional information would be provided by knowing the standard deviation?

Find the median for the given sample data. - $6,7,11,21,30,30,49$ Find the median for the data.

Use the range rule of thumb to approximate the standard deviation. -The heights in feet of people who work in an office are as follows. Round results to the nearest tenth. 5.9 6.0 5.5 5.4 5.9 5.5 5.6 6.2 5.8 5.5

Find the margin of error for the survey results described. -In a poll of 1534 adults, 35% said that they exercised regularly. Give your answer as a percentage to one decimal place.

Construct a boxplot as requested. -The test scores of 32 students are listed below. Construct a boxplot for the data set. 32 37 41 44 46 48 53 55 57 57 59 63 65 66 68 69 70 71 74 74 75 77 78 79 81 82 83 86 89 92 95 99

State how many peaks you would expect for the distribution described. -Speeds of everyone traveling on a country road, including cyclists and motorists

Provide an appropriate response. -Four different distributions are represented by the four boxplots below. Which distribution has the smallest median? Which has the greatest variation? Which is skewed to the left?

Find the standard deviation for the given data. Round your answer to one more decimal place than the original data. - $3,5,6,6,9,1$

A hypothesis test is to be performed. Describe the two possible outcomes of the test using the context of the givensituation. -Last month the average waiting time at a bank was $8.4$ minutes. The manager has installed a new computer system and claims that people will no longer have to wait as long. The hypotheses are as follows: Null hypothesis: average waiting time $= 8.4$ minutes Alternative hypothesis: average waiting time $< 8.4$ minutes

Use the 68-95-99.7 rule to solve the problem. -The time it take Claudia to drive to work is normally distributed with a mean of 48 minutes and a standard deviation of 5 minutes. What percentage of the time will it take her less than 53 minutes to Drive to work?

State how many peaks you would expect for the distribution described. -Voice pitch for the people in the school auditorium consisting of 6 year olds giving a concert, their mothers, and their fathers

Find the median for the given sample data. -A new business had the following monthly net gains: \ 6402 \ 1264 \ 3667 \ 7635 \ 7165 \ 3830 \ 1037 \ 8530 \ 5086 \ 5758 Find the median net gain.

Obtain the five-number summary for the given data. -The National Education Association collects data on the number of years of teaching experience of high-school teachers. A sample taken this year of 19 high-school teachers yielded the following Data on number of years of teaching experience. 33 13 1 21 31 8 3 12 2 23 25 1 33 28 6 18 24 22 31

Provide an appropriate response. -A criminal trial can be compared to a hypothesis test. The hypotheses are as follows: Null hypothesis: The defendant is innocent Alternative hypothesis: The defendant is guilty Suppose that in one trial, if convicted, the defendant will receive the death penalty. Do you think That a significance level of 0.05 or 0.01 is more appropriate in this case. Why?

State whether you think the difference between what occurred and what you would expect by chance is statisticallysignificant. -You draw a card at random from a deck of cards and replace it. You repeat this 100 times and get an ace 40 times.

Find a 95% confidence interval for the true population proportion. -In a poll of 1810 adults, 33% said that they exercised regularly.

Solve the problem. -The monthly incomes of trainees at a local factory are normally distributed with a mean of $1600 and a standard deviation $150. What percentage of trainees earn less than $1390 a month?

Find the median for the given sample data. -The normal monthly precipitation (in inches)for August is listed for 20 different U.S. cities. Find the median of the data. 3.5 1.6 2.4 3.7 4.1 3.9 1.0 3.6 4.2 3.4 3.7 2.2 1.5 4.2 3.4 2.7 0.4 3.7 2.0 3.6