Inferring Statistics

According to a random telephone survey, 85% of all working adults in the U.S. are satisfied with their current job. If I asked 500 adults, how many do you predict would be satisfied with their current job?

• 85 adults

• 340 adults

• 500 adults

• 425 adults

Zoie completes a report by asking 70 students across campus. She found that 48% of CTMS students do not wash their hands after using the bathroom. What is the population of her survey?

• the bathroom

• CTMS students

• 48% of students 

Biased or Random?

John wants to find out what the favorite soda flavor is at Menifee County. He decides to ask all the students in Mr. Goldsmith's class as a sample group.

• Biased

• Random

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 two answer choices.

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

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

The manager of a music store surveyed a random sample of customer who shop in the store about their favorite type of music. The table shows the number of customers who selected each type of music. Based on the information in the table, which inference about the favorite type of music of all the customers who shop in the music store appears to be valid?

• They are certain to select rock or pop music.

• They are less likely to select country or rap music than rock music.

• They are more likely to select country music than jazz, classical, or rap music.

• They are certain to select any type of music other than jazz music.

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.

The table shows the monthly sales at a pizza parlor for a 6-month period. Which statement is the best inference that can be made from the table?

• January had the lowest sales.

• The period with the greatest increase in monthly sales was from May to June.

• Sales for July will be greater than $10,000.

• The sales will drop over the next 2-month period.

Biased or Random?

Zane wants to determine the favorite candy among all 7th graders. So he asks all the people who sit in his row in Math class.

• Biased

• Random

A poll is taken from 100 seniors in a high school where the senior class has 575 students.

• Sample

• Population

At a middle school, the 7th graders will conduct a survey for where to go on a field trip. Which method will result in the least biased decision?

• to randomly ask 8th grade students who went on a field trip last year

• to randomly choose some 7th grade students to select a location

• to ask all 7th grade teachers and administrators for a location

• to ask the student council to choose a location