Inferences from Data

The following dot plots show the amount of time it takes each​ person, in a random​ sample, to complete two similar problems. Make a comparative inference about the two problems.

• The problems are equally challenging.

• Problem 2 is more difficult because it took students longer on average.

• Problem 1 is more difficult because it took students longer on average.

The following shows the number of calls two radio shows get each day for a ten day period. The two shows are on at the same time. Make a comparative inference based on the median values.

• Show 1 usually receives more calls.

• Show 2 usually receives more calls.

• The shows usually receive equal numbers of calls.

• There is not enough data to draw an inference.

In an effort to try to convince her mother that she is too old to join the intermediate swim​ class, Mira, who is 13 years​ old, gathers data on the ages of a random sample of members of the current intermediate swim class. The results of the data collected by Mira are displayed in the dot plot shown.

• It is likely that she will be able to convince her mother.​ Mira's age is within the area where the data are clustered.

• It is likely that she will be able to convince her mother.​ Mira's age is to the left of the area where the data are clustered.

• It is unlikely that she will be able to convince her mother.​ Mira's age is within the area where the data are clustered.

• It is unlikely that she will be able to convince her mother.​ Mira's age is to the left of the area where the data are clustered.

Mykel surveyed 15 7th graders and 15 8th graders at his school to see how many hours they spend per day listening to music. He made two box plots to compare the data sets. What inference can he draw from the data sets?

• The range is greater for the 8th graders, so there is greater variability for the 8th graders than the 7th graders.

• The person who listens to music the least is a 7th grader.

• The median is greater for the 7th graders, so they generally spend more time listening to music than 8th graders.

• No inferences can be made from the box plots.

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.

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 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.

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.

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.

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.