Question 1

Explain the difference between qualitative and quantitative variables noting the relationship of nominal,ordinal,interval,and ratio data to these terms.

Accepted Answer

The answer of Explain the difference between qualitative and quantitative...

Question 2

Sue took a test in both biology and math last week.The biology test had a mean of 70 and a standard deviation of 7 whereas the math test had a mean of 75 and a standard deviation of 10.Sue scored a 76 on the biology test and a 76 on the math test.On which test did she do better in comparison to the rest of the class?
A)the math test
B)the biology test
C)she did the same on each test
D)cannot be determined

Accepted Answer

To find out which test Sue did better on, we need to compare her scores to the rest of the class. To do this, we will convert Sue's scores to z-scores using the formulas: z = (x - mean) / standard deviation. For the biology test, Sue's z-score is (76 - 70) / 7 = 0.86. For the math test, Sue's z-score is (76 - 75) / 10 = 0.1. A higher z-score means the score is farther from the mean, indicating better performance relative to the rest of the class. Since Sue's z-score is higher for the biology test, we can conclude that she did better on the biology test compared to the rest of the class. Thus, the answer is B, the biology test.

Question 3

Faculty in the psychology department at State University consume an average of 5 cups of coffee per day with a standard deviation of 1.5.The distribution is normal.What proportion of faculty consumes an amount between 4 and 6 cups?
A).5468
B).4972
C).50
D)none of the options is correct

Accepted Answer

The answer of Faculty in the psychology department at State...

Question 4

If the shape of a frequency distribution is lopsided,with a long tail projecting longer to the right than to the left,how would the distribution be skewed?
A)normally
B)negatively
C)positively
D)average

Accepted Answer

A distribution with a long tail that projects further to the right than to the left is known as a positively skewed distribution. This is because the bulk of the data is on the left side of the distribution, causing it to be pulled to the right.

Question 5

Draw the frequency polygon for the following distribution (there are 30 scores in the distribution).In addition,calculate the mean,median,and mode for the distribution.
48,50,53,59,59,63,63,67,67,67,72,72,72,78,78,78,78,85,85,85,85,85,90,90,90,90,95,95,98,100

Accepted Answer

The answer of Draw the frequency polygon for the following...

Question 6

Rich's first psychology exam score is +1 standard deviation from the mean in a normal distribution.The test has a mean of 60 and a standard deviation of 6.Rich's percentile rank would be approximately
A)70%.
B)84%.
C)66%.
D)cannot determine from the information given

Accepted Answer

To find Rich's percentile rank, we need to find the area under the normal distribution curve to the left of his score. First, we need to standardize his score using the formula z = (x - mean) / standard deviation.

z = (x - 60) / 6 = 1

Using a standard normal distribution table or calculator, we can find that the area to the left of z = 1 is approximately 0.84. This means that approximately 84% of scores fall below Rich's score. Therefore, Rich's percentile rank would be approximately 84%.

Therefore, the correct choice is B.

Question 7

Imagine that distribution A contains the following scores: 3,4,5,6,7.Imagine that distribution B contains the following scores: 1,3,5,8,10.Distribution A has a _____ standard deviation and a _____ average deviation in comparison to distribution B.
A)larger; larger
B)smaller; smaller
C)larger; smaller
D)smaller; larger

Accepted Answer

The answer of Imagine that distribution A contains the following...

Question 8

Which of the following is a disadvantage of using the range as a measure of variation?
A)It is limited because only two of the scores in the distribution are used to derive it.
B)It is easily distorted by an unusually high or low score in a distribution.
C)It can only be used with nominal data.
D)It is limited because only two of the scores in the distribution are used to derive it and it is easily distorted by an unusually high or low score in a distribution.

Accepted Answer

Choice D is correct because it accurately identifies both limitations of using the range as a measure of variation. Only considering the two extreme scores in a distribution can be misleading, especially if there are outliers that significantly impact the range. Additionally, the range can be distorted by a single unusually high or low score in the distribution, which may not be representative of the rest of the data. Choices A, B, and C all describe limitations or issues with the range, but only D includes both major drawbacks.

Question 9

In a psychology class of 100 students,test scores are normally distributed with a mean of 80 and a standard deviation of 5.Approximately what percentage of students have scores between 70 and 90?
A)68%
B)80%
C)95%
D)99%

Accepted Answer

This problem requires finding the percentage of scores within one standard deviation of the mean. Using the empirical rule, we know that approximately 68% of scores fall within one standard deviation of the mean. Therefore, approximately 68% of students have scores between 75 (the score one standard deviation below the mean) and 85 (the score one standard deviation above the mean), which covers the range of 70 to 90. Therefore, option C is the correct answer.

Question 10

Faculty in the psychology department at State University consume an average of 5 cups of coffee per day with a standard deviation of 1.5.The distribution is normal.What is the percentile rank for an individual who consumed 8 cups of coffee per day?
A)97.72
B)2.28
C)47.72
D)none of the options is correct

Accepted Answer

To find the percentile rank of an individual who consumed 8 cups of coffee per day, we need to standardize this value by subtracting the population mean and dividing by the population standard deviation: (8-5)/1.5 = 2. 
Using a standard normal distribution table or calculator, we can find that the percentile rank associated with a z-score of 2 is approximately 97.72%, which is the answer choice A.

Question 11

Faculty in the psychology department at State University consume an average of 5 cups of coffee per day with a standard deviation of 1.5.The distribution is normal.How many cups of coffee would an individual at the 25^th percentile drink per day? A)4 B)5 C)6 D)7

Accepted Answer

We need to find the number of cups of coffee that an individual at the 25th percentile drinks. Since the distribution of number of cups of coffee consumed in the psychology department is normal, we can use the Z-score formula.

Z-score = (x - μ) / σ

where x is the value we want to find, μ is the mean of the population, and σ is the standard deviation of the population.

To find the Z-score corresponding to the 25th percentile, we can use a Z-score table or calculator. The Z-score for the 25th percentile is -0.67.

-0.67 = (x - 5) / 1.5

Solving for x, we get:

x = 5 - 1.005 ~= 4

Therefore, an individual at the 25th percentile would drink about 4 cups of coffee per day. So, the best choice is A.

Question 12

Explain the difference in proper use between a bar graph and a histogram.

Accepted Answer

The answer of Explain the difference in proper use between...

Question 13

If Joe scored 25 on a test with a mean of 20 and a standard deviation of 5 what is his z-score?
A)25
B)+1.0
C)0.0
D)cannot be determined

Accepted Answer

The z-score formula is:
z = (x - μ) / σ
where x is the value (in this case, Joe's score), μ is the mean, and σ is the standard deviation.

Substituting the given values:
z = (25 - 20) / 5
z = 1.0

Therefore, the z-score is +1.0, which corresponds to choice B.

Question 14

A z-score is most affected by the
A)median.
B)mode.
C)standard deviation.
D)range.

Accepted Answer

The z-score is calculated using the formula (x - mean) / standard deviation. Therefore, the standard deviation has the most direct impact on the z-score. The median, mode, and range do not have a direct impact on the z-score calculation.

Question 15

Approximately what percentage of scores are between z=1 and z=2?
A)50
B)68
C)16
D)13.5

Accepted Answer

In a standard normal distribution, approximately 13.5% of scores fall between z=1 and z=2.

Question 16

Which of the following is FALSE?
A)The range is a simplistic measure of variation that does not use all scores in the distribution in its calculation.
B)The average deviation is a more sophisticated measure of variation than the range in which all scores are used,but which may not weight extreme scores adequately.
C)The standard deviation is the least sophisticated measure of variation and the least frequently used.
D)all of the options are true

Accepted Answer

The statement in option C is false. The standard deviation is considered the most widely used and sophisticated measure of variation, as it uses all scores in the distribution and gives more weight to scores that deviate further from the mean.

Question 17

Calculate the mean,median,and mode for the following sample: 2,2,6,9,10,11,15,17,18,20.

Accepted Answer

The answer of Calculate the mean,median,and mode for the following...

Question 18

Karen's first psychology exam score is ?1 standard deviation from the mean in a normal distribution.The test has a mean of 75 and a standard deviation of 5.Karen's percentile rank would be
A)16%.
B)54%.
C)70%.
D)cannot determine from the information given

Accepted Answer

In a normal distribution, a score that is 1 standard deviation below the mean corresponds to the 16th percentile.

Question 19

If the average height for women is normally distributed with a mean of 65 inches and a standard deviation of 2.5 inches,then approximately 95% of all women should be between _____ and _____ inches in height.
A)62.5; 67.7
B)60; 70
C)57.5; 72.5
D)cannot determine from the information given

Accepted Answer

The 95% range in a normal distribution is within two standard deviations from the mean. So, 65 - 2(2.5) = 60 and 65 + 2(2.5) = 70.

Question 20

The calculation of the average deviation differs from the calculation of the standard deviation in that when calculating the average deviation the difference scores are
A)squared.
B)converted to absolute values.
C)squared and converted to absolute values.
D)it does not differ.

Accepted Answer

When calculating the average deviation, the difference scores are converted to absolute values. In contrast, when calculating the standard deviation, the difference scores are squared and then averaged.

Quiz 5: Data Organization and Descriptive Statistics

Explain the difference between qualitative and quantitative variables noting the relationship of nominal,ordinal,interval,and ratio data to these terms.

Faculty in the psychology department at State University consume an average of 5 cups of coffee per day with a standard deviation of 1.5.The distribution is normal.What proportion of faculty consumes an amount between 4 and 6 cups?

If the shape of a frequency distribution is lopsided,with a long tail projecting longer to the right than to the left,how would the distribution be skewed?

Draw the frequency polygon for the following distribution (there are 30 scores in the distribution).In addition,calculate the mean,median,and mode for the distribution. 48,50,53,59,59,63,63,67,67,67,72,72,72,78,78,78,78,85,85,85,85,85,90,90,90,90,95,95,98,100

Rich's first psychology exam score is +1 standard deviation from the mean in a normal distribution.The test has a mean of 60 and a standard deviation of 6.Rich's percentile rank would be approximately

Imagine that distribution A contains the following scores: 3,4,5,6,7.Imagine that distribution B contains the following scores: 1,3,5,8,10.Distribution A has a _ standard deviation and a _ average deviation in comparison to distribution B.

Which of the following is a disadvantage of using the range as a measure of variation?

In a psychology class of 100 students,test scores are normally distributed with a mean of 80 and a standard deviation of 5.Approximately what percentage of students have scores between 70 and 90?

Faculty in the psychology department at State University consume an average of 5 cups of coffee per day with a standard deviation of 1.5.The distribution is normal.What is the percentile rank for an individual who consumed 8 cups of coffee per day?

Faculty in the psychology department at State University consume an average of 5 cups of coffee per day with a standard deviation of 1.5.The distribution is normal.How many cups of coffee would an individual at the 25^th percentile drink per day?

Explain the difference in proper use between a bar graph and a histogram.

If Joe scored 25 on a test with a mean of 20 and a standard deviation of 5 what is his z-score?

A z-score is most affected by the

Approximately what percentage of scores are between z=1 and z=2?

Which of the following is FALSE?

Calculate the mean,median,and mode for the following sample: 2,2,6,9,10,11,15,17,18,20.

Karen's first psychology exam score is ?1 standard deviation from the mean in a normal distribution.The test has a mean of 75 and a standard deviation of 5.Karen's percentile rank would be

If the average height for women is normally distributed with a mean of 65 inches and a standard deviation of 2.5 inches,then approximately 95% of all women should be between _ and _ inches in height.

The calculation of the average deviation differs from the calculation of the standard deviation in that when calculating the average deviation the difference scores are

Quiz 5: Data Organization and Descriptive Statistics

Explain the difference between qualitative and quantitative variables noting the relationship of nominal,ordinal,interval,and ratio data to these terms.

Faculty in the psychology department at State University consume an average of 5 cups of coffee per day with a standard deviation of 1.5.The distribution is normal.What proportion of faculty consumes an amount between 4 and 6 cups?

If the shape of a frequency distribution is lopsided,with a long tail projecting longer to the right than to the left,how would the distribution be skewed?

Draw the frequency polygon for the following distribution (there are 30 scores in the distribution).In addition,calculate the mean,median,and mode for the distribution. 48,50,53,59,59,63,63,67,67,67,72,72,72,78,78,78,78,85,85,85,85,85,90,90,90,90,95,95,98,100

Rich's first psychology exam score is +1 standard deviation from the mean in a normal distribution.The test has a mean of 60 and a standard deviation of 6.Rich's percentile rank would be approximately

Imagine that distribution A contains the following scores: 3,4,5,6,7.Imagine that distribution B contains the following scores: 1,3,5,8,10.Distribution A has a _____ standard deviation and a _____ average deviation in comparison to distribution B.

Which of the following is a disadvantage of using the range as a measure of variation?

In a psychology class of 100 students,test scores are normally distributed with a mean of 80 and a standard deviation of 5.Approximately what percentage of students have scores between 70 and 90?

Faculty in the psychology department at State University consume an average of 5 cups of coffee per day with a standard deviation of 1.5.The distribution is normal.What is the percentile rank for an individual who consumed 8 cups of coffee per day?

Faculty in the psychology department at State University consume an average of 5 cups of coffee per day with a standard deviation of 1.5.The distribution is normal.How many cups of coffee would an individual at the 25th percentile drink per day?

Explain the difference in proper use between a bar graph and a histogram.

If Joe scored 25 on a test with a mean of 20 and a standard deviation of 5 what is his z-score?

A z-score is most affected by the

Approximately what percentage of scores are between z=1 and z=2?

Which of the following is FALSE?

Calculate the mean,median,and mode for the following sample: 2,2,6,9,10,11,15,17,18,20.

Karen's first psychology exam score is ?1 standard deviation from the mean in a normal distribution.The test has a mean of 75 and a standard deviation of 5.Karen's percentile rank would be

If the average height for women is normally distributed with a mean of 65 inches and a standard deviation of 2.5 inches,then approximately 95% of all women should be between _____ and _____ inches in height.

The calculation of the average deviation differs from the calculation of the standard deviation in that when calculating the average deviation the difference scores are

Imagine that distribution A contains the following scores: 3,4,5,6,7.Imagine that distribution B contains the following scores: 1,3,5,8,10.Distribution A has a _ standard deviation and a _ average deviation in comparison to distribution B.

Faculty in the psychology department at State University consume an average of 5 cups of coffee per day with a standard deviation of 1.5.The distribution is normal.How many cups of coffee would an individual at the 25^th percentile drink per day?

If the average height for women is normally distributed with a mean of 65 inches and a standard deviation of 2.5 inches,then approximately 95% of all women should be between _ and _ inches in height.