Populations Samples Inference

Litzy collects data from a random sample of 7th graders. Out of 40 respondents, 7 attend afterschool programs. Of the 200 7th graders attending Litzy's school, how many would be expected to attend afterschool programs?

• 14 7th graders

• 28 7th graders

• 35 7th graders

• 42 7th graders

The dot plot shows a random sample of the number of fish caught and released by 30 participants during a two-day fishing tournament. Select the inference that can be made based on the data collected.

• On average, most participants caught and released 5 or more fish.

• More participants caught 6 fish than any other number.

• The same participants who caught and released 1 fish the first day caught and released 1 fish on the second day.

• On average, participants caught and released more fish on Day 2.

There are 400 students at Polly's school. She surveyed a random sample of 80 students to find their favorite hobby. 19 said they like to read. 30 said they like to be with friends. 8 said they like to do crafts. 23 said they like to play sports. Polly infers that doing crafts is the least popular hobby at her school. Refer to the data table. Polly surveys two more samples. Do the results from these samples support the inference made from the first sample?

• Yes, the survey results support the inference that doing crafts is the least popular hobby at Polly's school.

• No, the survey results does not support the inference that doing crafts is the least popular hobby at Polly's school.

_______ is a part of a group being surveyed.

• Sample

• Population

• Random Sample

• Quartile

A travel club has 3,000 members. A random sample of 50 of the club members found that 12 people like mountain vacations best. Which statement is NOT supported by the sample data?

• Twenty-four percent of those sampled say they like mountain vacations best.

• An estimated 720 club members would likely say they enjoy mountain vacations best.

• Almost one-quarter of club members would likely say they enjoy mountain vacations best.

• More than 2,500 club members would likely say they prefer other vacations over mountain vacations.

What inference can you draw from this survey?

• I can infer that most students in this school like pizza.

• I can infer that very few students like hamburgers.

• I can infer that their favorite is corn dogs.

• I can infer that most students in this school like hamburgers.

When a sample does not accurately represent the population it is a:

• Unbiased sample

• Biased sample

The Magic Kingdom theme park has many attractions, one of which is Space Mountain. Are the people who ride Space Mountain the population, or a sample, of the theme park? Explain.

• Population. They are all the people at the theme park.

• Sample. They are a subset of all the people at the theme park.

• Both population and sample. They are all the people at the theme park

• Neither population nor sample. They are not the people at the theme park.

There are 400 students at Polly's school. She surveyed a random sample of 80 students to find their favorite hobby. 19 said they like to read. 30 said they like to be with friends. 8 said they like to do crafts. 23 said they like to play sports. Polly infers that doing crafts is the least popular hobby at her school. Yovani estimates that about 200 students in the school favor playing sports as a hobby. Do you agree?

• Yes, I used a proportion to find the number of students in the school who likely to prefer to play sports. 23/80 = 200/400; 200 students

• No, I used a proportion to find the number of students in the school who likely to prefer to play sports. 23/80 = 115/400; 115 students

The two data sets show the number of days that team members trained before a 5k race. What inference can you draw by comparing the median?

• There is more variability in the number of days that Team A members trained because the IQR for Team A is greater than the IQR for Team B.

• There is more variability in the number of days that Team B members trained because the IQR for Team B is greater than the IQR for Team A.

• Team A members generally trained for more days than Team B members

• Team B members generally trained for more days than Team A members