Question 1

Which of the following best describes a descriptive study in statistics?

Accepted Answer

A study that organizes and summarizes information about a specific group or time period.

Question 2

A researcher uses a random sample of 1000 people to estimate the percentage of people lacking health insurance in the U.S. This is an example of:

Accepted Answer

Inferential statistics

Question 3

Given the following scenario: 'A computer network manager tests 10 cables out of 400 to check reliability.' What is the sample and what is the population?

Accepted Answer

Sample: The 10 cables tested; Population: All 400 cables

Question 4

Which formula represents the probability of selecting one individual from a group of $$n$$ individuals?

Accepted Answer

$$\frac{1}{n}$$

Question 5

A school administrator wants to select a sample of students from a college with 120 freshmen, 90 sophomores, 110 juniors, and 80 seniors. If the administrator randomly selects 12 freshmen, 9 sophomores, 11 juniors, and 8 seniors, what type of sampling is used?

Accepted Answer

Stratified sampling

Question 6

An education researcher randomly selects 38 schools from one school district and interviews all the teachers at each of the 38 schools. What type of sampling is this?

Accepted Answer

Cluster sampling

Question 7

Which of the following statements about simple random sampling is TRUE?

Accepted Answer

Every possible sample of the desired size has an equal chance of being selected.

Question 8

A personnel manager randomly selects 20 software engineers and 20 hardware engineers from a company with 100 software engineers and 100 hardware engineers. Is this a simple random sample?

Accepted Answer

No, because not all possible samples are equally likely.

Question 9

If a researcher wants to estimate the birth rate per 1000 population for the years 1990-1994 and only summarizes the data, what type of statistics is being used?

Accepted Answer

Descriptive statistics

Question 10

Which of the following is NOT a characteristic of cluster sampling?

Accepted Answer

Individuals are randomly selected from each group.

Question 11

A researcher wants to select a sample such that every possible group of 40 employees from a company of 100 employees has an equal chance of being selected. What type of sampling is this?

Accepted Answer

Simple random sampling

Question 12

Which of the following best describes inferential statistics?

Accepted Answer

Drawing conclusions about a population based on sample data.

Question 13

A researcher uses a table of random numbers to select a sample. What is the main purpose of using random numbers in sampling?

Accepted Answer

To ensure that the sample is representative of the population.

Question 14

If a sample is not a simple random sample, which of the following is most likely TRUE?

Accepted Answer

Some samples are not possible to select.

Question 15

A researcher wants to estimate the percentage of people lacking health insurance in a city. She surveys a random sample of 500 residents and calculates the percentage. Which formula should she use to calculate the sample proportion $$\hat{p}$$?

Accepted Answer

$$\hat{p} = \frac{x}{n}$$

Question 16

Which sampling method is most appropriate when the population is naturally divided into groups and you want to randomly select entire groups?

Accepted Answer

Cluster sampling

Question 17

A company wants to select a sample of employees such that the sample reflects the proportion of software and hardware engineers in the company. Which sampling method should be used?

Accepted Answer

Stratified sampling

Question 18

If a sample is selected so that every individual has a $$\frac{1}{20}$$ chance of being chosen, what is the probability of selecting any one individual?

Accepted Answer

$$\frac{1}{20}$$

Question 19

Which of the following is a key difference between descriptive and inferential statistics?

Accepted Answer

Descriptive statistics summarize data; inferential statistics make predictions or generalizations about a population.

Question 20

A researcher wants to select a sample of 50 employees from a company of 200. She numbers the employees from 1 to 200 and uses a random number table to select the sample. What type of sampling is this?

Accepted Answer

Simple random sampling

Fundamental Concepts in Statistics: Descriptive, Inferential, Sampling Methods, and Random Sampling

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