Behavioral stats quiz #3

Scores from a statistics exam are reported as deviation scores. Which of the following deviation scores indicates a higher position in the class distribution?

+8

A population of N = 10 scores has μ = 50 and SS = 200. For this population, what is the value of ∑(X - μ)?

0

If all n = 10 individuals in a sample have exactly the same score, then the sample standard deviation will have a value of ________.

0

Without doing any serious calculations, which of the following samples has the largest variance?

1, 5, 8, 12, 22

A sample consists of n = 16 scores. How many of the scores are used to calculate the range?

2

A population of N = 10 scores has μ = 50 and SS = 200. For this population, what is the value of ∑(X - μ) 2 ?

200

If a sample has a variance of 16, then the sample standard deviation will be

4

A sample of n = 5 scores has SS = 40. If the same five scores were a population, then the value obtained for the population SS would be ________.

40

What does it mean to say that the sample variance is an unbiased statistic ?

If many different samples are selected, the average of the sample variances will be equal to the population variance.

What is the value of SS for the following sample? Scores: 1, 3, 5

SS = 8

For any set of data, the sum of the deviation scores will always be

equal to 0

A sample of n = 10 scores has SS = 90. For this sample, the variance is 9.

false

For a sample with a mean of M = 40 and a standard deviation of s = 8, a score of X = 34 would be considered an extreme value (out in the tail of the distribution).

false

If a population has a variance of 4, then the population standard deviation is 16.

false

A sample of n = 10 scores is selected from a population. The variability of the scores in the sample will tend to be ________ the variability of the scores in the population.

less than

A deviation score of -3 means that the score (X value) is three points below the mean.

true

A population of N = 10 scores has SS = 90. For this population, the variance is 9.

true

Degrees of freedom (df = n - 1) is used instead of n to compute sample variance to obtain an unbiased estimate of population variance.

true

For any population (or sample) the deviation scores will sum to zero.

true

If 10 points are added to every score in a distribution, then the value of the standard deviation will not be changed.

true

In general, the scores in a sample tend to be less variable than the scores in the population from which the sample was obtained.

true

It is impossible to obtain a negative value for SS.

true

A population of scores has μ = 50 and σ = 10. If every score in the population is multiplied by 2, then the new mean and standard deviation would be

μ = 100 and σ = 20

A population of scores has μ = 50 and σ = 10. If 5 points are added to every score in the population, then the new mean and standard deviation would be

μ = 55 and σ = 10

On an exam with a mean of μ = 70, you have a score of X = 75. Which of the following values for the standard deviation would give you the highest position within the class?

σ = 1