MATH217- Chapter 4

About 77% of young adults think they can achieve the American dream. Which of the following statements is true? (a) The distribution of sample proportions of young Americans who think they can achieve the American dream in random samples of size 40 is approximately normal since n ≥ 30. (b) A random sample of 60 young Americans where 85% think they can achieve the American dream would be considered unusual. (c) A random sample of 120 young Americans where 85% think they can achieve the American dream would be considered unusual. (d) Tripling the sample size will reduce the standard error of the sample proportion by one-third.

(c) A random sample of 120 young Americans where 85% think they can achieve the American dream would be considered unusual.

Which of the following statements accurately describe probability sampling? Select all that apply. (a) Probability sampling uses random selection. (b) Probability sampling can result in representative samples. (c) Probability sampling is typically inexpensive, convenient, and quick. (b) Probability sampling is based on the personal preferences of the researcher

A) Probability sampling uses random selection B) probability sampling can result in representative samples C) probability sampling is typically inexpensive, convenient, and quick

If sampled data is organized in such a way that it does not accurately represent its population as a whole, what problem will occur? (a) Biased data (b) Unclean data (c) Unfiltered data (b) Disorganized data

A) biased data

A gym wants to start offering exercise classes. A data analyst plans to survey 10 people to determine which classes would be most popular. To ensure the data collected is fair, what steps should they take? Select all that apply. (a) Increase the number of participants. (b) Collect data anonymously. (c) Survey only people who don't currently go to the gym. (b) Ensure participants represent a variety of profiles and backgrounds.

A) increase the number of participants B) collect data anonymously D) Ensure participants represent a variety of profiles and backgrounds

A data professional is conducting an election poll. As a first step in the sampling process, they identify the target population. What is the second step in the sampling process? (a) Select the sampling frame (b) Choose the sampling method (c) Determine the sample size (b) Collect the sample data

A) select the sampling frame

Which of the following statements accurately describe a sampling distribution? Select all that apply. (a) The distribution of a sample mean and the distribution of a sample proportion are examples of sampling distributions. (b) A sampling distribution is a probability distribution of a population parameter. (c) A sampling distribution can be visualized with a histogram. (b) A sampling distribution represents the probability distribution of a statistic under random sampling.

A) the distribution of a sample means and the distributions of a sample proportion are examples of sampling distributions C) A sampling distribution can be visualized with a histogram D) A sampling distribution represents the probability distribution of a statistic under random sampling.

What is a standard error? (a) The standard deviation of a sample statistic (b) An estimate of a population parameter (c) A list of all the items in the target population. (b) The probability distribution of a sample statistic

A) the standard deviation of a sample statistic

As the sample size increases the standard error of the sample mean________and the distribution of the sample mean becomes _________. The data________ become more normal. (a) decreases; wider; will (b) decreases; narrower; will not (c) increases; wider; will (d) increases; narrower; will (e) increases; stays the same; will no

B) decreases: narrower: will not

Which of the following best describes the central limit theorem? (a) The central limit theorem states that the mean of a population is always normally distributed. (b) The central limit theorem states that as the sample size increases, the sample mean approaches the population mean. (c) The central limit theorem states that as the sample size increases, the sampling distribution of the mean approaches a normal distribution, regardless of the distribution of the population. (b) The central limit theorem states that as the sample size increases, the variance of the population decreases.

B) the central limit theorem states that as the sample size increases the sample mean approaches the population mean

Which of the following statements best describes the law of large numbers? (a) The law of large numbers states that as the sample size increases, the sample mean becomes more variable. (b) The law of large numbers states that as the sample size increases, the sample mean approaches the population mean with increasing accuracy. (c) The law of large numbers states that as the sample size increases, the sample variance approaches the population variance. (b) The law of large numbers states that as the sample size increases, the sample becomes more biased.

B) the law of large numbers states that as the sample size increases the sample mean approaches the population mean with increasing accuracy

Fill in the blank: A business_______ data by collecting information from a significant number of users. This increases the likelihood that the data will be representative of the population as a whole. (a) averages (b) assigns (c) annotates (b) aggregates

D) aggregates

A data professional is analyzing data about a population of aspen trees. They take repeated random samples of 10 trees from the population and compute the mean height for each sample. Which of the following statements best describes the sampling distribution of the mean? (a) The sampling distribution of the mean is the sum of all the sample means. (b) The sampling distribution of the mean is the maximum value of all the sample means. ( c) The average value of all the sample means. (b) The probability distribution of all the sample means

D) the probability distribution of all the sample means

Non-probability sampling includes which of the following sampling methods? Select all that apply. (a) Purposive sampling (b) Convenience sampling (c) Systematic random sampling (b) Snowball sampling

a) Purposive sampling B) convenience sampling D) snowball sampling

Fill in the blank: A good sample is a segment of a population that is______ the entire population. (a) more diverse than (b) less diverse than (c) representative of (b) atypical of

C) representative of

Which of the following method can be used to estimate the variance, mean, and proportion of a population? (a) Sample mean (b) Sample variance (c) Point estimation (b) Regression analysis

c) Point estimation