### 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**