Descriptive & Inferential Statistics Quiz & Test Review

Identify the type of sampling method used in the situation below.

To determine the top four pizza toppings favored by its customers, a pizza place invites its customers to complete a survey.

• Self-Selected Sample

• Convenience Sample

• Simple Random Sample

• Stratified Sample

Answer explanation

To collect data about the number of students in your high school who have a part time job, which of the following methods is most likely to lead to a sample that is the most representative of the students in your school?

• Ask the principal.

• Interview all the students in 9th grade.

• Assign each student in the school a number and randomly select students to be interviewed.

• Interview all the girls in the school.

• Interview all the students who are on the sports teams in the school.

A survey of a random sample of voters predicts that Candidate A will receive 41% of the votes, Candidate B will receive 40% of the votes, and Candidate C will receive 9% of the votes. The margin of error is ±5%. Which statement is correct about the percent of votes that the candidates might get?

• Candidate C will definitely get the highest percentage.

• Candidate A will get between 36% and 46% of votes.

• Candidate B will not get the highest percentage of votes.

• A clear winner can be predicted based on these results.

Suppose x is a normally distributed random variable with mean μ = 75 and standard deviation σ = 4. Find the probability that 71 < x < 81.

• 84%

• 53%

• 77%

• 7%

The heights of the students in a class are normally distributed with a mean of 64 inches and a standard deviation of 3 inches. What is the probability that a randomly selected student is less than 59.5 inches tall?

• 50%

• 9.3%

• 7%

• 14%

The school principal wants to know if students like the school mascot. She asks 120 students throughout the day. Which of these is the sample?

• 120 students

• All the students that like the mascot

• All the students that do not like the mascot

• All the students in the school

You want to find out the top three food items sold in your school cafeteria.

Select the best way to generate a list of this data.

• Survey the students in your math class.

• Ask 10% of the students in each grade to tell you their choice for the top food item.

• Interview all the teachers about what they consider to be the top food item.

• Gather data about the number of sales of each food item from the cashier.

You want to determine the number of strikes thrown by a pitcher in a baseball game out of 100 pitches thrown. What type of study is this?

• 
  

  Survey

• 
  

  Observational Study

• Experiment

• Sample

During a meteor shower, Hannah counts how many meteors she sees each minute. During the first 5 minutes she sees 6, 4, 10, 3, and 7 meteors. If she sees 10 meteors in the next minute, how does this affect the mean and the standard deviation of the data

• During a meteor shower, Hannah counts how many meteors she sees each minute. During the first 5 minutes she sees 6, 4, 10, 3, and 7 meteors. If she sees 10 meteors in the next minute, how does this affect the mean and the standard deviation of the data

• The mean would decrease while the standard devaition increases.

• Both the mean and standard deviation would increase.

• Both the mean and standard deviation would decrease

An oil company plans to add a chemical to its gasoline to make it burn more cleanly. The company conducts an experiment to see whether adding the chemical affects the gasoline mileage of cars using their gasoline. State the null hypothesis for the experiment.

• Adding the chemical does not affect gasoline mileage.

• Adding the chemical affects gasoline mileage.

• Adding the chemical decreases gasoline mileage.

• Adding the chemical increases gas mileage.