PSM Exam 1
Which set of scores has the smallest standard deviation?
145, 143, 145, 147
A population of N = 10 scores has a mean of µ = 6. After one score is removed, the mean is found to be µ = 5. What is the value of the score that was removed?
15
For the following distribution of quiz scores, if a score of X = 3 or higher is needed for a passing grade, how many individuals passed? X f ____ 5 6 4 5 3 5 2 3 1 2
16
A sample consists of n = 16 scores. How many of the scores are used to calculate the range?
2
A population has a sum of the squared deviation scores, SS = 100 and a variance, σ 2 = 4. How many scores are in the population?
25
For the population of scores shown in the frequency distribution table, the mean is ____. X f ____ 5 2 4 1 3 3 2 2 1 2
29/10 = 2.90
For the population of scores shown in the frequency distribution table, the mean is ____. X f ____ 5 2 4 1 3 3 2 2 1 2
29/10=2.90
A sample of n = 25 scores has mean M = 20 and variance s2 = 9. What is the sample standard deviation?
3
For the following distribution of quiz scores, How many individuals had a score of X = 2? X f ____ 5 6 4 5 3 5 2 3 1 2
3
A population has a mean of µ = 30. If 3 points are added to each score, what is the mean for the new distribution?
33
A sample of n = 6 scores has Σ X = 30. What is the sample mean?
5
After every score in a sample is multiplied by 3, the mean is calculated and found to be M = 21. What was the mean for the original scores?
7
After a researcher adds 5 points to every score in a sample, the standard deviation is found to be s = 10. The original sample had a standard deviation of s = 5
False
For a 100-point exam, a score of X = 65 is definitely above the median.
False
For the following distribution of scores, Σ X = 10. X f ____ 4 1 3 2 2 3 1 2
False
It is impossible for the value of the mode to be greater than the value of the mean.
False
A sample of scores has M = 50 and s = 5. If every score in the sample is multiplied by 3, then what are the new values for the mean and standard deviation?
M=150 and S=5
A population with a mean of µ = 6 has Σ X = 42. How many scores are in the population?
N=42/6=7
A positive deviation score always indicates a score that is greater than the mean.
True
For a sample with M = 20 and s = 1, a score of X = 17 would be considered an extremely low score.
True
For a particular sample of size n=10, the largest distance (deviation) between a score and the mean is 11 points. The smallest distance between a score and the mean is 4 points. Therefore, the standard deviation will be ____.
between 4 and 11
For a 100-point exam, a score of X = 65 is definitely above the median.
false
It is impossible for the value of the mode to be greater than the value of the mean.
false
For a negatively skewed distribution with a mean of M = 20, what is the most probable value for the median?
greater than 20
A distribution of scores has a mean of µ = 50. One new score is added to the distribution and the new mean is found to be µ = 48. From this result, you can conclude that the new score was ____.
less than 50
A researcher obtains eye color from a sample of n = 50 people. Which measure of central tendency would be appropriate to summarize the measurements?
mode
A distribution is positively skewed. Which is the most probable order, from smallest to largest, for the three measures of central tendency?
mode, median, mean
The students in a psychology class seemed to think that the midterm exam was very easy. If they are correct, what is the most likely shape for the distribution of exam scores?
negatively skewed
A population has µ = 50 and σ = 5. If 10 points are added to every score in the population, then what are the new values for the mean and standard deviation?
u=60 and o=5
The students in a psychology class seemed to think that the midterm exam was very easy. If they are correct, what is the most likely shape for the distribution of exam scores?
negatively skewed
