Quiz 3 - Sampling & Sampling Distribution

A researcher identifies professional athletes as the group of interest to test her research hypothesis. She then identifies a few local professional teams and selects a small group of local athletes to be observed. In this example, who is the target population?

• The target population is not identified.

• The target population is all professional athletes.

• The target population is the few local professional athletes.

• The target population is the small group of professional athletes who were observed.

Which category of sampling is used when the probability of selecting each individual in a population is known, and every member of the population has an equal chance of being selected?

• Probability sampling

• Nonprobability sampling

• Both probability and nonprobability sampling could be correct.

• Neither probability nor nonprobability sampling could be correct.

A beverage company wanted to see if people in the United States like their new logo. Which choice best represents a population?

• A selection of logo artists

• 3,800 children age 5-15

• Every person in the United States

• A selection of shoppers from different states

A restaurant chain wanted to find out the rate of customers’ experience in the store. Which choice best represents a statistic?

• All customers

• A random selection of customers that were surveyed.

• The percentage of all customers that reported a positive experience.

• The percentage of customers surveyed that reported a positive experience.

A school principal wants to see which subject did the 845 students in his school like best. Which choice best represents a parameter?

• 845 students

• 120 students surveyed

• 700 of the 845 students prefer math

• 100 of the 120 students surveyed prefer math.

Consider a population that is normally distributed. If the average of the population is 8.5, what is the mean of its sampling distribution?

• 7

• 7.5

• 8

• 8.5

Consider a population that is normally distributed. If the standard deviation of the population is 2 and the sample size is 9, what is the standard deviation of the sampling distribution of sample means?

• 0.22

• 0.44

• 0.67

• 1.33

Cellular phone bills for residents of a city have a mean of P1, 000 and a standard deviation of P170. Random samples of 100 cellular phone bills are drawn from this population and the mean of each sample is determined. Find the standard deviation of the sampling distribution of the sample means.

• 7

• 9

• 17

• 71

Researchers found that boys playing football absorbed an average of 355 hits in the head with a standard deviation of 80 hits during a season.  What is the probability on a randomly selected team of 48 players if the average number of head hits per player is between 340 and 360?

• 0.236

• 0.429

• 0.571

• 0.614

Suppose the teenagers that attend public high schools get an average of 5.7 hours of sleep each night with a standard deviation of 1.7 hours.  What is the probability of a randomly selected group of 35 high school students getting more than 6 hours of sleep each night?

• 0.087

• 0.148

• 0.281

• 0.430