STATS Exam 1

Statistics is the study of methods and procedures for: -Collecting data. -Summarizing data. -Analyzing data. -All of the previous answers.

All of the previous answers

In your sock drawer, you have 4 blue, 5 grey, and 3 black socks. Half asleep one morning, you grab 2 socks at random and put them on. What is the probability you are wearing matching socks?

0.288

Given the probabilities shown below, what is P(A⋂B)? P(A) = 0.65, P(B) = 0.32, and P(B|A) = 0.75

0.4875

1380 randomly sampled registered voters from El Paso, Texas were asked if they thought workers who have illegally entered the US should be (i) allowed to keep their jobs and apply for US citizenship, (ii) allowed to keep their jobs as temporary guest workers but not allowed to apply for US citizenship, or (iii) lose their jobs and have to leave the country. The results of the survey by political ideology are shown below What percent of these El Paso, Texas voters who identify themselves as conservatives are also in favor of the citizenship option?

20.0%

Which of the following is an example of quantitative/Numerical data?

Apple's closing stock price today.

Suppose you have a data set with the following five-number summary: Minimum = 26, Q1 = 32, Median = 34, Q3 = 38, Maximum = 58. What is the lower cutoff point for potential outliers? (By lower cutoff point, we mean the number such that anything smaller than it is an outlier).

23

The boxplot below shows the distribution of heights of 16 undergraduate statistics students. Using this boxplot, approximately how many students are 69 inches or taller?

4

A researcher is interested in learning how often college students watch TV. They randomly select 500 college students and ask, "In the past seven days, how many days did you watch television?" The random variable x represents the number of days an individual watched television. The probability distribution below shows the results of the survey. What is the expected value of X?

5.44

What is the interquartile range (IQR) of the following data set? 3,4,5,6,8,10,16

6

The monthly average high temperatures for New York City have the following five-number summary: the minimum is 40, the median is 63, the third quartile is 77, the interquartile range (IQR) is 32, and the maximum is 84. Which of these shows the correct box-and-whisker plot for the data?

A

The BBC reported that on average college students drink 33 ounces of alcohol per week. CNN picked up the story because in the US the average is only 24 ounces per week. Assume we want to test if that average is different for TAMU students, so we hire surveyors from all over the state of Texas, and they randomly select 100 students from the athletics department at A&M. They find the average is 16 ounces per week. What is the population that these results are valid for?

Athletic students at Texas A&M

The histogram shown below represents 40 student scores on a statistics exam. (Two peaks) Which of the following best describes the shape of the scores?

Bimodal

A researcher wants to determine if a new exercise program helps people lose weight. She recruits over 1200 subjects (her statistician determined this number from sample size calculations) and randomly assigns them to either participate in the new exercise program or no exercise program. She tells those in the new program group to exercise 3 times a week and tells those in the no exercise group that they should not exercise for the duration of the study. Based on this information, which of the following principles of experimental design is not present in this study?

Blinding

Consider the list below of different sampling methods. Which of these sampling methods are not probability samples? -Simple Random Sample. -Convenience Sample. -Cluster Sample. -Stratified Sample. -Voluntary Sample.

Convenience and Voluntary Samples

If a fair coin is tossed many times and the last eight tosses are all heads, then the chance that the next toss will be head is somewhat less than 50%.

False

Based on the scatterplot below, which of the following statements is correct about the head length and skull width of possums?

Head length and skull width are positively associated.

Consider the following set of data: 2, 3, 4. What is the standard deviation?

SD=1.00

The Educational Testing Service (ETS) needed a sample of colleges. ETS first divided all colleges into 6 subgroups of similar types (small public, small private, medium public, medium private, large public, and large private). Then they randomly selected 3 colleges from each group. The sampling method used is:

Stratified Random Sample

Which of the following best describes the term mutually exclusive?

The property of events in which none can occur at the same time.

Taylor Swift is interested in learning what proportion of her fans watched her premiere Betty live at the ACM Awards on September 16, 2020. She takes a simple random sample of 500 fans and asks them. Of the 500 fans, 475 of them (95%) respond that they watched her perform. What is the statistic and what is its value?

The statistic is the proportion of the sampled Taylor Swift fans who watched the performance, which is 0.95.