Inference Sampling

See the image.

• 15 Students

• 25 Students

• 30 Students

• 50 Students

Answer the questions above.

• 123

• 156

• 36

• 64

A judgement that is made by interpreting data

• Inference

• Sample

• Variability

• Comparative Inference

A movie theater randomly samples the types of admission tickets sold on Friday in the afternoon and the evening. If 400 tickets are sold on a Friday afternoon, use your inference and proportional reasoning skills to determine how many of those 400 tickets would be adult tickets. Type your numerical answer only.

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.

A representative sample of 80 customers in a clothing store was surveyed about how they paid for their purchases. The table shows the responses. Based on the results, which of the following are valid inferences. Select all that apply.

• Tomorrow, 8 out of the first 80 customers will for sure pay with a gift card.

• In a group of 40 customers, it is expected that about 10 will pay with cash.

• About 0.3, or 30%, of all the store's customers will pay with a credit card.

• A sample of 100 customers would provide less reliable data.

Using your inference skills and proportional reasoning, predict the number of purple jellybeans in a bag of 200 total jellybeans if a random sample of 25 resulted in 4 purple jellybeans. I predict there will be _________ purple jellybeans.

Johanna was running for class president. She wanted to know if she had a good chance of winning the election, so she decided to have her classmates help her with surveys. Michael surveyed a random sample of 10 students from the school. 7 of them said they would vote for Johanna. If there are 230 students in the school, and all of them vote, what is Michael’s best estimate of the number of students who would vote for Johanna? _________ students