Generalizations Based on Random Samples

The process of drawing conclusions using valid data from samples and making generalizations about a population.

• Validity

• Random Sample

• Sample

• Inferential Statistic

A large company has facilities across the country. The facilities director was asked to survey employees about their office furniture. Rather than survey all employees in the company, the director decided to take a sample of the employees. Which groups would be most representative of the opinions of all employees of the company? Select each correct answer

• Employees with office numbers ending in 3 and 7

• Randomly selected employees in the cafeteria of one of the offices

• 5% of randomly selected employees from each office location

• Employees answering phone calls in the company's customer service department

• Employees who are randomly selected by a computer from a list of all company employees

Josephine owns a diner that is open every day for breakfast, lunch, and dinner. She offers a regular menu and a menu with daily specials. She wanted to estimate the number of customers who order daily specials. She selected a random sample of 50 customers who had lunch at her diner during a three-month period. She determined that 28% of these customers ordered from the menu with specials. Which statement about Josephine's sample is true?

• The sample is the percentage of customers who order daily specials

• The sample might not be representative of the population because it only included lunch customers

• The sample shows that exactly 28% of Josephine's customers ordered daily specials

• No generalizations can be made from the sample, because the sample size of 50 is too small

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.

Identify the Sample: The Huddle House wants to know if their customers buy dessert when they eat out. As people leave the restaurant one evening, 20 people are surveyed at random. Eight people say they usually order dessert when they eat out. The manager at Huddle House concluded that most customers do not order dessert. What is the SAMPLE in this scenario?

• 20 customers from Huddle House

• All customers from Huddle House that evening

• 8 customers from Huddle House

• The employees from Huddle House

Based on the results of Gabrielle's survey, how many of the 840 students who eat in the cafeteria can be expected to eat tomato the soup?

Three students surveyed random samples of 40 students out of 840 students that eat in the cafeteria each day. The results of the three surveys are shown in the table. Based on the results of the three surveys, what percentage of the 840 students who eat in the cafeteria each day can be expected to eat the tomato soup?

• About 35%

• About 14%

• About 29%

• About 4%

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Ethan surveyed 120 registered voters at random out of a total of 12,600 registered voters in his town. He asked them who they planned to vote for in the upcoming election. The results are shown in the table.

Based on the results of the survey, how many people are expected to vote for Ms. Gibson in the upcoming election?

Maribelle surveyed 120 voters in her town each day of the week. The town has 12,600 registered voters. Based on the results shown in the table of the survey each day, what is the best prediction for how many more votes Ms. Reynolds is expected to receive than Ms. Gibson in the upcoming election?

• Approximately 1,500 to 2,500 more votes

• Approximately 2,500 to 3,500 more votes

• Approximately 3,500 to 4,500 more votes

• Approximately 4,500 to 5,500 more votes