### Standard Deviation, Independent Variable – Final Test – STATS

The key terms in these Statistics chapters include Distribution, Variable, Quasi-independent variable, Standard Deviation, Normal Distribution, Correlation, z-score Distribution, Sample, Population, – Final Test – Stats

A doctor is measuring children’s heights to the nearest inch and obtains scores such as 40, 41, 42, and so on. What are the real limits for a score of X = 42?

**41.5 and 42.5**

A quasi-independent variable is most similar to and consistent with which of the following terms?

**Non-equivalent groups research study**

Which of the following statements is consistent with a research study conducted with the correlational method?

**Two variables are measured, and there is only one group of participants.**

Assuming that SS Y is constant in a research study, which of the following correlations would have the largest SS residual?

**r = – 0.10**

A normal distribution has a mean of µ = 60 with σ = 8. For this population, which is the X value that corresponds to the third quartile?

**X = 65.36**

Which proportion of a normal distribution is located between the mean and z = +1.40?

**0.4192**

In order to determine if 10 points below the mean on an exam is an extreme negative score, the _____ needs to be known.

**Standard deviation**

2% of scores fall between the z scores ________ and ________.

**2;3**

In a STANDARD NORMAL DISTRIBUTION, approximately ________% of scores fall within 2 standard deviations from the mean

**96**

A z-score distribution ________ has a mean of ________.

**Always; 0**

What are the values for SS and variance for the following sample of n = 4 scores? Scores: 1, 3, 0, 4

**SS = 10 and variance = 3.33**

Which set of scores below has the smallest standard deviation? a. 5, 11, 42, 22 b. 27, 105, 10, 80 c. 145, 143, 145, 147 d. 11, 17, 31, 53

**b. 145, 143, 145, 147**

A doctor is measuring children’s heights to the nearest inch and obtains scores such as 40, 41, 42, and so on. What are the real limits for a score of X = 42?

**41.5 and 42.5**

A quasi-independent variable is most similar to and consistent with which of the following terms?

**Non-equivalent groups research study**

Which of the following statements is consistent with a research study conducted with the correlational method?

**Two variables are measured, and there is only one group of participants.**

Assuming that SS Y is constant in a research study, which of the following correlations would have the largest SS residual?

**r = – 0.10**

The sum of the squared deviation scores is SS = 20 for a sample of n = 6 scores. What is the variance for this sample?

**s2 = 4**

The law of large numbers states that larger samples are _____.

**Usually more representative of a population**

If the individuals in a sample have characteristics that are noticeably different from the individuals in the population, then the sample is said to be ____.

**Biased**

The most commonly used sampling method in psychological research is probably ____ sampling

**Convenience**

A systematic sample does not qualify as a true random sample because ____.

**The selections are not independent of each other**

There’s a type of validity that usually needs multiple research studies over a long period of time. Which is it?

**Construct**

Consider the mathematical expressions of (Σ X) 2 and Σ X 2. A valid generalization is that _____.

**The first equation will yield a higher computed value**

Standard Deviation Final Test – Statistics

Which of the following is a description of DATA (rather than a datum)?

**Individual scores of 15 participants on a problem-solving task**

For a research study examining how participant gender influences support for equality in society, participant gender is an example of which kind of variable?

**Quasi-independent variable**

A vertical line is drawn through a normal distribution at z = -1.20. Which proportion of the distribution is on the right-hand side of the line?

**0.8849 (body)**

A class consists of 10 male and 30 female students. A random sample of n = 3 students is selected with replacement. If the first two students are both females, what is the probability that the third student is a male?

**p = 10/40**

Which of the following is a requirement for a random sample?

a. There must be sampling with replacement.

b. Every individual has an equal chance of being selected.

c. The probabilities cannot change during a series of selections.**d. All of the above are correct**

Which position in a distribution corresponds to a z-score of z = -1.00?

**Below the mean by 1 standard deviation**

Tom scores an X = 43 on an exam with a mean of µ = 52. Tom’s score is associated with a z-score of -1.80. What is the value for the exam standard deviation?

**σ = 5**

Under which circumstance is a score that is 15 points above the mean an extreme score relatively far from the mean?

**When the population standard deviation is much smaller than 15**

A sample has M = 71 and s = 3. In this sample, what is the X value corresponding to z = +1.33?

**X = 75**

If an entire population with µ = 60 and σ = 8 is transformed into z-scores, then the distribution of z-scores will have a mean of _____ and a standard deviation of _____.

**µ = 0; σ = 1.**

A population of scores has µ = 10 and σ = 2. If every score in the population is multiplied by 4, then what are the new values for the mean and standard deviation?

**µ = 40 and σ = 8**

Consider a population that has a score of X = 15 associated with a z-score of +1.50. What does this z-score indicate about the location of X = 15?

**A score of X = 15 is 1.5 standard deviations above the mean.**

Corey scores X = 70 on his first exam, for which the entire class scored a mean of µ = 78 and standard deviation of σ = 6. The instructor wants to standardize the distribution of exam scores to have µ = 100 and σ = 15. What will Corey’s grade on the exam be in the new distribution?

**X = 80**

A score that is 3 points lower than the sample mean has a z-score of z = -0.25, and a score of X = 44 has a z-score of -0.75. What is the sample mean?

**M = 53**

A doctor is measuring children’s heights to the nearest inch and obtains scores such as 40, 41, 42, and so on. What are the real limits for a score of X = 42?

**41.5 and 42.5**

A quasi-independent variable is most similar to and consistent with which of the following terms?

**Non-equivalent groups research study**

Which of the following statements is consistent with a research study conducted with the correlational method?

**Two variables are measured, and there is only one group of participants.**

Assuming that SS Y is constant in a research study, which of the following correlations would have the largest SS residual?

**r = – 0.10**

Which of the following is a requirement for a random sample?

a. There must be sampling with replacement.

b. Every individual has an equal chance of being selected.

c. The probabilities cannot change during a series of selections.**d. All of the above are correct**

Which position in a distribution corresponds to a z-score of z = -1.00?

**Below the mean by 1 standard deviation**

Tom scores an X = 43 on an exam with a mean of µ = 52. Tom’s score is associated with a z-score of -1.80. What is the value for the exam standard deviation?

**σ = 5**

Under which circumstance is a score that is 15 points above the mean an extreme score relatively far from the mean?

**When the population standard deviation is much smaller than 15**

Standard Deviation Final Test – Statistics