# Population & Mean And Standard Deviation – Statistics

### Population & Mean And Standard Deviation, Square Root & Variability – Stats

The key terms discussed in these Statistics chapters Population, Square Root, Mean And Standard Deviation, Sample, Square Root of 50 & Variability.

A population of N = 10 scores has μ = 50 and σ = 5. What is the population variance?

25

A sample of n = 5 scores has M = 20 and s2 = 4. What is the sample standard deviation?

2

The value for the INTERQUARTILE RANGE is determined by ____.

The middle scores in the distribution

For any set of data, the sum of the deviation scores (that is, deviations from the mean) will always be ___.

Equal to zero

In a population of N = 10 scores, the smallest score is X = 8 and the largest score is X = 20. The range for the population is ____. (the data are discrete; and there is no need to use real limits)
12

In a population with a mean of μ = 50, a score of X = 45 would have a deviation score of ____.

-5

A population of N = 10 scores has μ = 50 and σ = 5. What is the population variance?

25

On average, what value is expected for the t statistic when the null hypothesis is true?

0

A sample of n=25 scores has M=20 and s^2=9. What is the sample standard deviation?
3

A sample of n=6 scores has a standard deviation of s=3. What is the value of SS, the sum of squared deviations for this sample?
45

A sample of n = 5 scores has M = 20 and s2 = 4. What is the sample standard deviation?

#### 2

A population of N = 5 scores has SS = 40. What is the variance for this population?

40/5 = 8

A population has SS = 30 and σ2 = 6. How many scores are in the population?

N = 5

To compute SAMPLE variance, the value of SS is divided by ____.

n – 1

To compute POPULATION variance, the value of SS is divided by ____.
N

What is the value of SS (sum of squared deviations) for the following population?
Population: 1, 1, 1, 5
12

A population of N=10 scores has a standard deviation of σ=2. What is the value of SS, the sum of the squared deviations, for this population?

40

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

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 sample of n=8 scores has SS=50. If these same scores were a population, then the SS value for the population would be ___.

##### 50

A researcher conducts a hypothesis test using a sample from an unknown population. If the t statistic has df = 30, how many individuals were in the sample?

n = 31

With α = .01, the two-tailed critical region for a t test using a sample of n= 16 subjects would have boundaries of ______.

t = ±2.947

The smallest score in a population is X = 5 and the largest score is X = 10. Based on this information, you can conclude that ____.

The population mean is between 5 and 10, and the standard deviation is less than 5

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

What is the value of SS for the following set of scores? Scores: 1, 1, 1, 3

#### 3

What is the variance for the following population of scores? Scores: 5, 2, 5, 4

1.5

If all n = 10 individuals in a sample have exactly the same score, then the sample standard deviation will have a value of ____.
0

Which of the following samples would have the largest value for sample variance?

All the samples would have exactly the same variance.

Which set of scores has the least amount of variability?

145, 143, 145, 147

For a particular sample, 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 ____.

Is probably between 4 and 11

A sample of n=8 scores has SS=50. If these same scores were a population, then the SS value for the population would be ___.

50

A researcher conducts a hypothesis test using a sample from an unknown population. If the t statistic has df = 30, how many individuals were in the sample?

n = 31

With α = .01, the two-tailed critical region for a t test using a sample of n= 16 subjects would have boundaries of ______.

t = ±2.947

The smallest score in a population is X = 5 and the largest score is X = 10. Based on this information, you can conclude that ____.

The population mean is between 5 and 10, and the standard deviation is less than 5

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

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