Stat Attack!

The stem-and-leaf plot shows the number of push-ups completed in PE class by a sample of boys and girls. What is the mean for each data set, rounded to the nearest whole number?

Key: 8 | 1 | 0 = 18 and 10

1. The mean for boys is 26 and the mean for girls is 22.
2. The mean for boys is 22 and the mean for girls is 26.
3. The mean for boys is 30 and the mean for girls is 25.
4. The mean for boys is 25 and the mean for girls is 30.

The histogram shows the hours of TV watched per week by 30 students. Which statement is TRUE?

1. More than half of the students watched 6 or more hours of TV per week.
2. The most common range was 3–5 hours per week.
3. Exactly 14 students watched 4 hours of TV per week.
4. The same number of students watched 6–8 hours as watched 9 or more hours.

A baker is preparing 200 cupcakes for a wedding. To check the sweetness, she randomly tastes 8 cupcakes (tough job, somebody's gotta do it) and decides they're perfect. Fill in the blanks:

Mr. Patel wants to know which school lunch is most popular. He needs a sample of 30 students. Which of the following are random samples?

1. Choose the first 30 students who walk into the cafeteria.
2. Survey the football team and the cheer squad.
3. Number every student in the school and pull 30 numbers from a bingo machine.
4. Post on social media and use the first 30 students to reply.
5. Use a random number generator to select 30 student IDs from the full school roster.
6. Survey 30 of your closest friends.

A survey of 4,500 middle schoolers showed that 3 out of 5 students prefer pizza over tacos. (Bold choice. Tacos are amazing.) How many students surveyed prefer pizza?

1. 1,500
2. 2,700
3. 1,800
4. 3,000

You give a survey to your soccer team asking how many goals each player scored last season. A national sports league later decides to use your team's results to estimate the average number of goals scored by all middle school soccer players in the country. What is the population for this problem?

1. Your soccer team
2. Soccer players who scored at least one goal
3. All middle school soccer players in the country
4. Professional soccer players

Two sets of data are graphed on the dot plot below. Set 1 is shown with circles (●), Set 2 with X marks. What observation can you make about the two data sets?

1. The means of the two data sets are about 25 points apart.
2. The medians of the two data sets are 10 points apart.
3. Both data sets have a mode of 40.
4. Both data sets have a range of 50.

Which back-to-back stem-and-leaf plot correctly represents the data sets shown below?

Maya wants to know which TV shows are most popular among teenagers in her town. She decides to survey the first 20 people leaving the gym on Saturday morning. Which statements about her sample are true?

1. This sample includes the entire teenage population.
2. This sample excludes teenagers who don't go to the gym.
3. This sample is biased toward people who exercise.
4. This sample is representative of all teenagers in town.
5. This sample is NOT a random sample.
6. This sample is a random sample.

Mr. Lee recorded the minutes he spent on his phone each day for two weeks. The results are shown. What is the IQR (Interquartile Range) for each week?

1. The IQR for Week 1 is 16, and the IQR for Week 2 is 14.
2. The IQR for Week 1 is 14, and the IQR for Week 2 is 16.
3. The IQR for Week 1 is 23, and the IQR for Week 2 is 32.
4. The IQR for Week 1 is 29, and the IQR for Week 2 is 33.