Z-Scores q&a
A defining characteristic of normal curve is that they are: - (CORRECT
ANSWER)theoretical
A proportion or area under the curve can also represent the: - (CORRECT
ANSWER)probability of a score occurring
A social researcher has constructed a measure of racial prejudice and obtained a
distribution of scores on this measure from a randomly selected sample of public office
holders. The scores were normally distributed with a mean of 45 and a standard
deviation of 7. What is the approximate probability that a randomly selected case from
the sample will have a score less than 38? - (CORRECT ANSWER).1587
A standard normal curve will have a mean of _____ and a standard deviation of _____.
- (CORRECT ANSWER)0, 1
A student's score on her midterm exam was at the 50th percentile and the grades were
normally distributed. The exam average was 78 and the standard deviation was 6. What
was her score on the exam? - (CORRECT ANSWER)78
A z-score of -3.0 means: - (CORRECT ANSWER)that the score is below the sample
mean.
A z-score of 2.3 on a normally distributed measure corresponds to a percentile rank of: -
(CORRECT ANSWER)98.93
Approximately how many people would have scores LOWER than an individual with a
z-score of 1.96? - (CORRECT ANSWER)97.5%
Approximately what percentile rank is associated with a z-score of +1.00? - (CORRECT
ANSWER)84
, As the standard deviation of a normal distribution increases, the proportion of the area
between ±1 standard deviation will: - (CORRECT ANSWER)stay the same
As used in the social sciences, probabilities are a type of _____ which can vary from
_____. - (CORRECT ANSWER)proportion, 0.00 to 1.00
Assuming a normal distribution of 1,000 cases, how many cases will be farther away
from the mean than +3 standard deviations? - (CORRECT ANSWER)about 1
By definition, the normal curve is - (CORRECT ANSWER)symmetrical
Compare the scores: a score of 220 on a test with a mean of 200 and a standard
deviation of 21 and a score of 90 on a test with a mean of 80 and a standard deviation
of 8. - (CORRECT ANSWER)A score of 90 with a mean of 80 and a standard deviation
of 8 is better.
Converting a score to a z-score allows a researcher to: - (CORRECT ANSWER)locate
where a score falls in a distribution and describe how it compares to other scores in the
distribution.
Converting scores into z- scores standardizes the original distribution to units of the: -
(CORRECT ANSWER)standard deviation
For all normal curves the area between the mean and ±1 standard deviation will be: -
(CORRECT ANSWER)68.26% of the total area
Given a population distribution of women's heights with a mean of 5 feet 6 inches, which
value is least probable? - (CORRECT ANSWER)6 feet 1 inch
A defining characteristic of normal curve is that they are: - (CORRECT
ANSWER)theoretical
A proportion or area under the curve can also represent the: - (CORRECT
ANSWER)probability of a score occurring
A social researcher has constructed a measure of racial prejudice and obtained a
distribution of scores on this measure from a randomly selected sample of public office
holders. The scores were normally distributed with a mean of 45 and a standard
deviation of 7. What is the approximate probability that a randomly selected case from
the sample will have a score less than 38? - (CORRECT ANSWER).1587
A standard normal curve will have a mean of _____ and a standard deviation of _____.
- (CORRECT ANSWER)0, 1
A student's score on her midterm exam was at the 50th percentile and the grades were
normally distributed. The exam average was 78 and the standard deviation was 6. What
was her score on the exam? - (CORRECT ANSWER)78
A z-score of -3.0 means: - (CORRECT ANSWER)that the score is below the sample
mean.
A z-score of 2.3 on a normally distributed measure corresponds to a percentile rank of: -
(CORRECT ANSWER)98.93
Approximately how many people would have scores LOWER than an individual with a
z-score of 1.96? - (CORRECT ANSWER)97.5%
Approximately what percentile rank is associated with a z-score of +1.00? - (CORRECT
ANSWER)84
, As the standard deviation of a normal distribution increases, the proportion of the area
between ±1 standard deviation will: - (CORRECT ANSWER)stay the same
As used in the social sciences, probabilities are a type of _____ which can vary from
_____. - (CORRECT ANSWER)proportion, 0.00 to 1.00
Assuming a normal distribution of 1,000 cases, how many cases will be farther away
from the mean than +3 standard deviations? - (CORRECT ANSWER)about 1
By definition, the normal curve is - (CORRECT ANSWER)symmetrical
Compare the scores: a score of 220 on a test with a mean of 200 and a standard
deviation of 21 and a score of 90 on a test with a mean of 80 and a standard deviation
of 8. - (CORRECT ANSWER)A score of 90 with a mean of 80 and a standard deviation
of 8 is better.
Converting a score to a z-score allows a researcher to: - (CORRECT ANSWER)locate
where a score falls in a distribution and describe how it compares to other scores in the
distribution.
Converting scores into z- scores standardizes the original distribution to units of the: -
(CORRECT ANSWER)standard deviation
For all normal curves the area between the mean and ±1 standard deviation will be: -
(CORRECT ANSWER)68.26% of the total area
Given a population distribution of women's heights with a mean of 5 feet 6 inches, which
value is least probable? - (CORRECT ANSWER)6 feet 1 inch
