Sampling Methods Answers

Lorrie wants to determine the average amount of time that students at her school spend on the computer each day. There are 350 students in 15 classes. The number of boys and girls is approximately equal. Which is the most random sample?

Kari plans to sample 20 people of a population that contains 100 students. She wants to determine how many people wake up before 6 a.m. Which sample is the most random?

A group of tourists is determining the order in which to visit national landmarks in Washington, DC. The group contains 200 people. Of those people, 150 are adults, and 50 are children. A random sample of tourists in the group is chosen. Surveying the random sample produced a representative sample of the population. Which was most likely true of the representative sample?

Mikayla designed a survey to determine the number of people expected at opening night of a community theater. The community has about 5,000 members. She selected a sample of the first 25 parents dropping off actors during theater rehearsal. Which best explains Mikayla’s sample?

Chelsea wants to determine the number of people in her school who read news reports on the Internet daily. She asks five people in her language arts class. Which improvements could Chelsea make to her sample to increase the validity of the results? Select three options.

Charles wants to find out if the students in foreign language classes spend more time in class speaking in English or in the foreign language they are studying. Charles first gets class lists of all students taking foreign language classes. He then chooses 10 students from each different language class to survey. Which best explains why the sample he chose may not be a representative sample?

A bicycle factory installs about 400 tires per day. Tires are installed Monday through Friday for 8 hours per day. The manager of the factory estimates the number of properly installed tires per week using the process below.In the first hour of work on Monday, 49 out of 50 tires were properly installed. So, there were about 8(49) = 392 properly installed tires on Monday.Considering 5 working days per week, 5(392) = 1,960 is the number of tires properly installed in one week.Which best explains the validity of the results?

The chart below shows the distribution of the number of books in a library.Sahira chooses a random sample from the library and records the type of books in the chart below.Type of BookNumberFantasy10Literature25Children’s4Nonfiction11Which explains whether or not Sahira’s sample is representative?

The chart below shows the distribution of weeds in a yard. A lawn-care specialist chooses a random sample from the yard and determines the number of weeds in the sample. The results of the sample are shown in the table below.Weed TypeNumberDandelion2Clover3Crab Grass2Chickweed2Which explains whether or not this is a representative sample?

Lamont designs a survey of town residents in an attempt to predict who will be elected mayor. He chooses his sample of 500 people from the town’s 40,000 residents by asking his question to every person leaving the public library on a Saturday. Which suggestion would most improve Lamont’s random sample?

Perry performs a study to determine the average number of flowers on gardenia bushes at a plant nursery. Which will produce the most representative results?

Kelvin and Lewie each design surveys in order to determine the average number of people who buy food at the mall. Kelvin surveys every other person leaving the food area. Lewie surveys every fifth person leaving the mall’s main entrance. Which set of survey results is most likely to show biased results for people who buy food at the mall?