Question 1

Which measure of variability uses only two data points?

Accepted Answer

The range is the measure of variability that uses only two data points, the maximum and minimum values in the dataset. The standard deviation and variance require the use of all data points in the calculation, while the median only represents the middle value in a dataset and not the variability.

Question 2

Which descriptive statistic is least likely to be influenced by the presence of skewness?

Accepted Answer

The median is the middle value of a dataset, and is not influenced by extreme values or outliers, making it the least likely to be influenced by skewness. The standard deviation and mean are both sensitive to outliers and extreme values, while the range is affected by the smallest and largest values in the dataset.

Question 3

If I wanted to determine,on average,how far apart any one score is from another,I should use a measure of

Accepted Answer

Variability measures how spread out or dispersed a set of scores is. It would be the appropriate measure if one wants to determine the average distance between any two scores. Central tendency measures the middle or typical score, correlation measures the relationship between two variables, and statistical significance refers to the likelihood that a result occurred by chance. None of these measures directly pertain to the average distance between scores.

Question 4

Which measure of central tendency is used when asking about national income levels,wherein 50 percent of the population makes more than this amount and 50 percent of the population makes less?

Accepted Answer

The median represents the middle value in a dataset when the values are arranged in order. In this scenario, the median income level would represent the income at which 50% of the population makes more and 50% makes less. The mean (B) could be affected by outliers or extremely high or low values, which might not be representative of the majority of the population. The mode (C) refers to the most frequently occurring value in a dataset and may not provide information about the distribution of income levels. The range (A) would only provide information about the difference between the highest and lowest income levels, which may not be representative of the overall distribution of income.

Question 5

This mathematical method allows researchers to determine whether they can generalize findings from a sample to the full population.

Accepted Answer

Inferential statistics allow researchers to make predictions or generalizations about a population based on data collected from a sample. Standard deviation and descriptive statistics are used to summarize and describe the characteristics of a sample, but they do not directly address the question of generalizability. Differential statistics is not a commonly used term in statistics.

Question 6

Which measure of central tendency is used when you are asked what is the most number of cigarettes you smoked in a day over the past week?

Accepted Answer

The mode would be the most appropriate measure of central tendency in this case since we are interested in finding the most common value, which is the number of cigarettes smoked in a day over the past week. The mode represents the most frequently occurring value and will give us an idea of what the typical number of cigarettes smoked in a day is for that particular week.

Question 7

Measures of __________ reflect how loosely or tightly bunched scores are in a distribution,whereas measures of __________ reflect where the group of scores tends to cluster.

Accepted Answer

Measures of variability (such as standard deviation or range) reflect how loosely or tightly bunched scores are in a distribution, whereas measures of central tendency (such as mean, median or mode) reflect where the group of scores tends to cluster.

Question 8

Most people in general are quite happy,but there are some instances of mild depression,fewer cases of moderate depression,and even fewer cases of severe depression.What could you say about the distribution of depression in the general population?

Accepted Answer

The distribution is positively skewed because there are more instances of mild depression and fewer instances of severe depression, creating a tail on the right side of the distribution.

Question 9

A researcher wishes to generalize his findings beyond the people at the organization he is studying in Alberta.He wants to attempt to show that the findings apply to all people who work in a similar type of organization throughout Canada.He should use __________ to analyze his data.

Accepted Answer

Inferential statistics is used when a researcher wants to generalize the findings of their study to a larger population beyond the sample that was studied. In this case, the researcher wants to apply the findings to all people who work in a similar type of organization throughout Canada, which requires making inferences about the larger population. Therefore, inferential statistics would be the best choice for analyzing the data.

Question 10

This simplest measure of variability is the

Accepted Answer

The range is the simplest measure of variability as it only requires the maximum and minimum values in the data set. The other options (standard deviation, mode, and mean) are more complex measures of variability.

Question 11

Suppose at the movie theatre you observe that a few patrons arrive early,but most arrive just moments before the movie begins,and no one arrives late.What could you say about the distribution of patron arrivals at the theatre?

Accepted Answer

Since most patrons arrive just moments before the movie begins, the distribution is skewed to the left (or negatively skewed).

Question 12

Which measure of central tendency uses all the available data?

Accepted Answer

The mean uses all of the available data points to calculate the average, making it the best choice for a measure of central tendency that uses all the data. The median only considers the middle value(s), while the mode only considers the most frequently occurring value(s). The standard deviation is a measure of variability, not central tendency.

Question 13

The __________ reflects the middle score in a data set,whereas the __________ reflects the most frequent score.

Accepted Answer

The median reflects the middle score in a data set, which is the value that separates the higher half from the lower half. On the other hand, the mode reflects the most frequent score, which is the value that appears most often in the data set. Therefore, the best choice is (D) median;mode.

Question 14

When a distribution is skewed,which of the following descriptive statistics would offer the best measure of central tendency?

Accepted Answer

When the distribution is skewed, the mean is influenced by extreme values and may not be a good measure of central tendency. In this case, the median, which is the middle value, is a better measure of central tendency. Therefore, the best choice is the median (choice B). The standard deviation (choice C) and range (choice D) are not measures of central tendency, but rather measures of dispersion.

Question 15

A British literature instructor examines the number of class periods his students have missed by mid-terms and has the following data: 1,0,10,0,2,1,0,0,5,2,3,0,0,0,1,1,2,3,1.What is the mode for this data set?

Accepted Answer

The mode is the number that appears most frequently in a data set. In this data set, the number 0 appears most frequently.

Question 16

Suppose in a classroom of students you hear a few watches chime at the top of the hour,then more watches chime,then a few again.Not one watch chimed with any other,but likely the most chimes occurred at the true top of the hour.What could you say about the distribution of watch chimes in the classroom?

Accepted Answer

The answer of Suppose in a classroom of students you...

Question 17

Which measure of dispersion uses all the available data?

Accepted Answer

Standard deviation uses all the available data to measure the dispersion and variability of a dataset.

Question 18

Suppose in your kitchen you watch the popcorn kernels pop in the popper.A few kernels pop early,a few kernels pop late,but most pop in between.What could you say about the distribution of kernel popping?

Accepted Answer

The distribution of the kernel popping is likely to be normally distributed, since most kernels pop in between and a few may pop early or late. A normal distribution is characterized by a symmetrical bell-shaped curve, with the majority of the data clustered in the middle and fewer data points in the tails.

Question 19

A British literature instructor examines the number of class periods his students have missed by mid-terms and has the following data: 1,0,10,0,2,1,0,0,5,2,3,0,0,0,1,1,2,3,1.What is the median for this data set?

Accepted Answer

The median is the middle value of a data set when it is ordered from least to greatest. The ordered data set is: 0,0,0,0,0,0,1,1,1,1,1,2,2,2,3,3,5,10. The middle value is 1.

Question 20

Suppose in a classroom of students some arrive early to class,but most students arrive just moments before class begins,and no one comes in after class has started.What could you say about the distribution of student arrival to class?

Accepted Answer

The fact that most students arrive just moments before class begins indicates a preponderance of late arrivals, which implies a negatively skewed distribution.

Quiz 2: D: Research Methods