Question 1

The maximum height of a normal curve corresponds to the ________ of a normal distribution.

Accepted Answer

The maximum height of a normal curve corresponds to the mean of the normal distribution.

Question 2

Lee believes that if someone walks under a ladder,they will have bad luck.His belief is based on his experience with people walking under a ladder and then having bad luck.Lee's belief is an example of

Accepted Answer

Lee's belief is a classic example of illusory correlation, where people perceive a connection between two unrelated events based on a personal belief or experience, rather than actual evidence or statistics. In this case, Lee believes that walking under a ladder causes bad luck, despite there being no empirical evidence to support this claim.

Question 3

A negative correlation between people's work-related stress and their marital happiness would indicate that

Accepted Answer

The answer of A negative correlation between people's work-related stress...

Question 4

Which of the following events is the most probable?

Accepted Answer

The answer of Which of the following events is the...

Question 5

Jwa would like to display the descriptive statistics for a study he has just completed.The simplest and most visual way of this would be for him to construct a

Accepted Answer

A bar graph is the simplest and most visual way of displaying descriptive statistics. It allows for quick comparisons between different categories or groups and can display measures such as mean, median, and mode. A normal curve, range, or skewed distribution may be used to display specific types of data, but do not provide an overall summary of descriptive statistics.

Question 6

Differences between two sample averages are most likely to be statistically significant if

Accepted Answer

The larger the difference between the means of two samples, the more likely it is that the difference is statistically significant. This is because a larger difference means there is less overlap between the two distributions, making it more unlikely that the difference occurred by chance. The other options are not necessarily indicative of statistical significance; large standard deviations may increase variability within each sample, making it harder to detect a significant difference, and samples drawn from the same population may have identical means. Sample means being larger than sample medians is also not necessarily related to statistical significance.

Question 7

Ahmed has five sisters who are 3,3,5,9,and 10 years of age.The number "5" represents the ________ of the sisters' ages.

Accepted Answer

The median is the middle value in a list of numbers sorted in ascending or descending order. In the given ages of 3, 3, 5, 9, and 10, the number 5 is the middle value, making it the median.

Question 8

In a data set of 10,10,9,9,8,7,7,7,6,5,5,and 4,what is the mode?

Accepted Answer

The mode is the value that appears most frequently in the data set. In this case, the number 7 appears three times, which is more than any other number in the set. Therefore, the mode is 7.

Question 9

When people's negative moods are at their worst,whatever they do to try to alleviate the condition is likely to be followed by an improvement in their mood rather than further worsening.This is best explained in terms of

Accepted Answer

This phenomenon is best explained by the statistical concept of regression toward the mean, which suggests that extreme events or conditions are likely to be followed by more average or typical outcomes. Therefore, when people's negative moods are at their worst, it is likely that their mood will improve simply due to this regression effect rather than any specific intervention they may try.

Question 10

Which measure of central tendency is Dr.Smith likely to use to summarize his data if his goal is to examine the average scores?

Accepted Answer

The mean is the best choice for examining average scores as it takes into account all values in the data set and is sensitive to changes in the values. The median and mode are not as useful for examining average scores as they only focus on one value in the data set and may not represent the overall trend. The standard deviation is a measure of variability, not central tendency.

Question 11

In a single day,45 babies were born in hospital X,65 babies in hospital Y,and 25 babies in hospital Z.At which hospital is there the greatest probability that more than 60 percent of the babies are of the same sex?

Accepted Answer

Hospital Z, with the fewest babies (25), has the greatest probability that more than 60 percent of the babies are of the same sex. This is because smaller sample sizes are more likely to deviate significantly from expected ratios (such as the near 50/50 sex distribution in larger populations), making it easier for a small group to have a higher percentage of one sex.

Question 12

Researchers organize data using

Accepted Answer

Descriptive statistics are used to organize and summarize data through measures of central tendency (mean, median, mode) and measures of variation (standard deviation, range). Inferential statistics, correlation coefficient, and measures of variation are used to analyze and draw conclusions from the data.

Question 13

A statistically significant difference between two sample groups is NOT likely to be

Accepted Answer

The answer of A statistically significant difference between two sample...

Question 14

A sample average can be used to estimate a population average with greater precision if the sample is

Accepted Answer

A larger sample size provides a more accurate representation of the population, reducing the potential for sampling error and increasing the precision of the estimated population average. Skewed distribution, high variability, and vividness do not necessarily affect the precision of the sample mean in estimating the population mean.

Question 15

One person in a 10-person group is 10 times older than anyone else in the group.With respect to age,it is most likely that the majority of group members are younger than the group's

Accepted Answer

Given one person is significantly older, this outlier increases the mean age more than the median or mode, making the majority younger than the mean.

Question 16

________ means that the observed differences between scores is probably not due to chance variation between the samples.

Accepted Answer

Statistical significance is the term used to describe the likelihood that the differences observed between two groups or samples is not due to chance. This is typically determined by calculating a p-value, which is the probability that the observed differences occurred by chance. If the p-value is less than a predetermined significance level (usually 0.05), then the differences are considered statistically significant.

Question 17

If a negative correlation between two sets of scores is displayed in a scatterplot,the points are clustered in a pattern that

Accepted Answer

A negative correlation means that as one variable increases, the other variable decreases. When displayed in a scatterplot, this relationship is shown by a cluster of points that extends from the upper left to the lower right. Option B describes a positive correlation and options A and C do not accurately describe the pattern of a negative correlation.

Question 18

To decide whether observed differences between samples reflect actual differences between populations,you should determine the ________ of the observed differences.

Accepted Answer

To determine if observed differences are statistically significant, we need to examine the p-value or significance level. This tells us the likelihood that the differences we observe occurred by chance and not due to true differences between populations. Therefore, choice D (statistical significance) is the best option. Mean, median, and standard deviation are measures of central tendency and variability within a sample, but they do not directly indicate if the differences between samples are statistically significant.

Question 19

Mrs.Smith is measuring the height of all the children in her class and notices that the scores form a symmetrical,bell-shaped distribution.This is also known as the

Accepted Answer

A symmetrical, bell-shaped distribution is characteristic of a normal curve. This means that the majority of the scores cluster around the mean, with fewer scores on either extreme end. The normal curve is important in statistical analysis and allows researchers to make predictions and draw conclusions about a population based on sample data.

Question 20

Random samples provide ________ estimates of population averages if the samples have small ________.

Accepted Answer

Random samples provide good estimates of population averages if they have small variability. The smaller the variability, the more representative the sample will be of the overall population, and the more accurate the estimate of the population average will be. Therefore, option B, which states that random samples provide good estimates if they have small variability, is the best choice.

Quiz 16: Statistical Reasoning in Everyday Life