Question 1

In a test marked study,206 out of a sample of 560 people state that they "liked" the product being studied.The proportion of people in this study who said that they liked this product was about:

Accepted Answer

The proportion of people who liked the product is calculated as (206/560) * 100 = 36.7857%, which rounds to approximately 37%.

Question 2

The confidence interval increases as the sample size,n,increases.

Accepted Answer

the confidence interval decreases as the sample size increases.

Question 3

The value below which half the values in a distribution fall is the ____.

Accepted Answer

The value below which half the values in a distribution fall is the median. The mean is the average value of the distribution, the mode is the most frequently occurring value, and the range is the difference between the maximum and minimum values in the distribution.

Question 4

Three factors are required to specify sample size: (1)the variance of the population;(2)the population mean;and (3)the confidence level.

Accepted Answer

three factors are required to specify sample size: (1)the variance of the population;(2)the magnitude of acceptable error;and (3)the confidence level.

Question 5

Which of the following is not a measure of the central tendency of a set of scores?

Accepted Answer

Range is a measure of variability, not central tendency. The mode, median, and mean are all measures of central tendency.

Question 6

The measure of central tendency that identifies the value that occurs most often is called the ____.

Accepted Answer

The mode is the measure of central tendency that identifies the value that occurs most often.

Question 7

Nicole has created a table that summarizes the number of times a particular value of a variable occurs.Nicole has created a ____ distribution.

Accepted Answer

Nicole has created a frequency distribution because she is summarizing how often a particular value occurs. A parameter is a summary measure of a population, a normal distribution is a specific type of probability distribution, and a probability distribution involves assigning probabilities to different values in a distribution.

Question 8

Summary measures about variables computed using only data taken from a sample are called sample:

Accepted Answer

Sample statistics are summary measures computed from a sample, as opposed to parameters which are derived from the entire population.

Question 9

Find the mean score of the following set of scores: 2,5,7,4,8.

Accepted Answer

To find the mean score, we add up all the scores and divide by the total number of scores. 
(2+5+7+4+8)/5 = 26/5 = 5.2
Therefore, the best choice is B.

Question 10

Which of the following refers to the proportion of respondents who choose the most positive choice in a multiple choice question?

Accepted Answer

The top-box score is the proportion of respondents who choose the most positive choice in a multiple choice question. Heteroskedasticity refers to the unequal variances in a dataset, mode refers to the most frequently occurring data point, and median refers to the middle value in a dataset.

Question 11

Increases in sample size reduce sampling error at a decreasing rate.

Accepted Answer

As sample size increases, the decrease in sampling error becomes less and less substantial. This is because sampling error is influenced by factors beyond sample size, such as the variability within the population being sampled. Therefore, while increasing sample size is generally a good way to reduce sampling error, the benefit of doing so diminishes as sample size grows larger.

Question 12

The arithmetic average of a set of numbers is referred to as the _____.

Accepted Answer

The arithmetic average of a set of numbers is referred to as the mean.

Question 13

The ____ is a measure of dispersion.

Accepted Answer

Range is a measure of dispersion that calculates the difference between the highest and lowest values in a dataset. The mean, mode, and proportion are measures of central tendency, not dispersion.

Question 14

Suppose the average units produced in a month by a Ford Motor Co.plant for Ford Explorers is 22,but only 18 Explorers are produced on a given day in that same month.Then,the deviation score for this one day is ____.

Accepted Answer

The deviation score is calculated by subtracting the actual value from the average value. In this case, 18 (actual) - 22 (average) = -4.

Question 15

Suppose the price of MP3 players in Denver range from $59 to $179.Then,the range of these prices is ____.

Accepted Answer

Range is the difference between the highest and lowest values in a set of data. Therefore, the range of these prices would be $179 - $59 = $120. Thus, the best choice would be B, which represents the value of $120.

Question 16

The formula below is used to calculate the ____.

Accepted Answer

The formula shown is used to calculate the sample mean, which is the sum of all observations in the sample divided by the sample size.

Question 17

A researcher must calculate the sample mean to calculate the confidence intervals.

Accepted Answer

To calculate confidence intervals, the researcher needs to know the sample mean.

Question 18

In most cases,the size of the population does not have a major effect on the sample size.

Accepted Answer

The size of the population typically does not have a significant impact on the necessary sample size. Other factors, such as the level of desired precision and the variability within the population, are typically more important in determining sample size.

Question 19

When a researcher wants to estimate national market share based on the results of the test market for a new product in St.Louis and Kansas City,this is an example of:

Accepted Answer

Inferential statistics are used to generalize data from a sample to a larger population. In this case, the researcher is using the results of the test market (sample) to infer the national market share (population). Descriptive statistics (A) describe the characteristics of the data, the central limit theorem (B) is a theoretical concept regarding the distribution of sample means, and the standardized normal distribution (D) is a specific type of probability distribution.

Question 20

____ is the long-run relative frequency with which an event will occur.

Accepted Answer

Probability is the long-run relative frequency with which an event will occur.

Quiz 13: Big Data Basics: Describing Samples and Populations