*Chapter 17: Standard scores and normal distributions( FINAL) sd and mean
a test of reaction times has a mean of 10 and a standard deviation of 4 in the normal adult population. What score (to the nearest whole number) would cut off the highest 10% of scores?
15
a normally distributed set of scores has a mean of 40 and a standard deviation of 8.
22.0.
the mean for a population is 500, with a standard deviation of 90; the scores are normally distributed. The proportion of scores which lie above 650 is:
0.0475.
the mean for a population is 500, with a standard deviation of 90; the scores are normally distributed. The proportion of scores between 300-400 is:
0.1203.
the mean for a population is 500, with a standard deviation of 90; the scores are normally distributed. The proportion of scores which lie between 460 and 600 is:
0.5365
a normally distributed set of scores has a mean of 40 and a standard deviation of 8. A z score of 1.25 corresponds to a raw score of:
50.
What percentage of the population would have scores up to and including 14 on this test?
84.13.
a normally distributed set of scores has a mean of 40 and a standard deviation of 8. The percentage of scores between 32-44 is:
53.28.
A group of patients has a mean weight of 80 kg, with a standard deviation of 10 kg. You are told that a patient's weight is two standard deviations below the mean. What is this patient's weight?
60 kg.
the mean for a population is 500, with a standard deviation of 90; the scores are normally distributed. The raw score which lies at the 90th percentile is:
615.20
a standard normal distribution. The percentage of cases falling between z = 20.5 and z = 12 is:
66.9%.
a standard normal distribution. The percentage of cases falling between z = 21 and z = 11 is:
68.3%.
a normally distributed set of scores has a mean of 40 and a standard deviation of 8. The percentile rank of a raw score of 48 is
84.13
the mean for a population is 500, with a standard deviation of 90; the scores are normally distributed. The percentile rank of a score of 667 is
96.86
z = 1.28 cuts off the highest 10% of scores in a normal distribution.
T
z scores express how many standard deviations a particular score is from the mean.
T
z = 22.58 has a percentile rank of 98 in a normal distribution.
F
The area of a normal curve between any two designated z scores expresses the proportion or percentage of cases falling between the two points.
T
In a normal curve, approximately 34% of the scores fall between z = 0 and z = 21.
T
A group of patients has a mean weight of 80 kg, with a standard deviation of 10 kg. You are told that a patient's weight is two standard deviations below the mean. What is this patient's weight?
half of all children will need treatment for longer than 8 weeks.
A percentile rank:
tells you what percentage of scores fall at or below a particular score.
What is the percentile rank of a score of 8 on this test?
30.85.
a standard normal distribution. The percentage of cases falling above z = 0.35 is:
36.3%.
a standard normal distribution. The percentage of cases falling either below z = 22 or above z = 12 is:
4.6%.
a test of reaction times has a mean of 10 and a standard deviation of 4 in the normal adult population. A person scores 8. That person's z score is:
20.5.
A group of patients has a mean weight of 80 kg, with a standard deviation of 10 kg. What is the standard score (z) for a patient whose weight is 50 kg?
23.
a normally distributed set of scores has a mean of 40 and a standard deviation of 8. The raw score which cuts off the lowest 5% of the population (rounded to the nearest whole number) is:
27
Which of the following statements is true?
All the above statements are true.
50% of scores fall between z = 0.5 and z = 20.5.
F
A percentile rank represents the number of cases falling above a particular score.
F
About 10% of scores fall 3 standard deviations above the mean.
F
If 20% of scores fall into a given class interval, then the percentile rank of the upper real limit of the class interval is 20.
F
In a normal distribution, the higher the z score, the higher will be the frequency of the corresponding raw score.
F
Negative z scores are further from the mean than positive z scores.
F
Notwithstanding the level of skewness in a distribution, the standard normal curve is useful for determining the percentile rank of a score.
F
The greater the value of and s, the greater the value of the z scores in corresponding standard distributions.
F
A standardized distribution has the same shape as the distribution from which it was derived.
T
Even when the distribution of raw scores is skewed, the standardized distribution will be normal.
T
Given a bimodal distribution of raw scores, the standard normal curve is inappropriate for calculating percentile ranks.
T
Numerous human characteristics are distributed approximately as a normal curve.
T
The mean of a standard normal distribution is always 1.0.
T
The percentile rank of z = 0 is always 50.
T
The z scores of three persons X, Y and Z in a statistical methods test were 12.0, 11.0 and 0.0, respectively. In terms of the original raw scores, which of the following statements is true?
The raw score difference between X and Y is equal to the raw score difference between Y and Z.
In an anatomy test, your result is equivalent to a standard or z score of 0.2. What does this z score imply?
Your result was slightly above average.
