Statistic or Parameter
Sample SD (s)
Sample Size (n)
Probability Given Sample SD
Attributes of Central Limit Theorem (Challenge Problems)
100
Of all of the varsity football players at H.D. Woodson 95% plan to go to college after graduation
Parameter because the team is a population
100
The population has a mean of 14 and a standard deviation of 3. What is the sample standard deviation for a group N = 25?
s = 0.6
100
The population has a mean of 14 and a standard deviation of 3. How many samples must be drawn to reduce the standard deviation to 1?
N = 9
100
The population has a mean of 14 and a standard deviation of 3. What is the probability that someone in a SAMPLE group of 25 people will score a 16 or below? Report s, z-score, and probability.
s = 0.6 z = 3.33 p = 99.96%
100
The mean of the population is ____________ to the mean of the sample
equal
200
100 teachers were surveyed and 84% graded papers on the weekend
Statistic, because it is a sample of 100 teachers
200
The population has a mean of 30 and a standard deviation of 6. What is the mean of the sample? What is the sample standard deviation for a group N = 49
s = 0.86
200
The population has a mean of 30 and a standard deviation of 6. How many samples must be drawn to reduce the sample standard deviation to 3?
N = 4
200
The population has a mean of 30 and a standard deviation of 6. What is the probability that someone in a SAMPLE group of 36 people will score a 27 or below? Report s, z-score, and probability.
s = 1 z = -3.00 p = 0.13%
200
a low standard deviation tells you scores are ____________ _______________
close together
300
30,000 college freshmen were admitted to a University. After the first week, the University surveyed 1,000 and found that 81% were satisfied with their dorms.
Statistic because the University only surveyed a group of 1,000 students
300
The population has a mean of 120 and a standard deviation of 12. What is the mean of the sample? What is the sample standard deviation for a group N = 36
s = 2
300
The population has a mean of 120 and a standard deviation of 12. How large of a sample is needed to reduce the sample standard deviation to 4?
N = 9
300
The population has a mean of 120 and a standard deviation of 12. What is the probability that someone in a SAMPLE group of 36 people will score a 123 or above? Report s, z-score, and probability.
s = 2 z = 1.50 p = 6.68%
300
a high standard deviation tells you scores are ____________ _______________
far apart
400
The overall class quiz average was a 75%
Parameter because the class is a population.
400
The class average on a quiz was an 88% with a standard deviation of 5. What is the sample standard deviation for a group of 10 students?
s = 1.58
400
The class average on a quiz was an 88% with a standard deviation of 5. How many students would you need to sample to reduce the standard deviation to 0.5?
N = 100
400
The class average on a quiz was an 88% with a standard deviation of 5. What is the probability that someone in a SAMPLE group of 36 people will score a 90% or above? Report s, z-score, and probability.
s = 0.83 z = 2.41 p = 0.8%
400
What happens to the sample standard deviation as the sample size increases? what happens to s as n increases?
the sample standard deviation decreases
500
Consumer reports research center states that of all men, 34% purchase clothes online.
Parameter, because all men are a population
500
The average number of hours a high schooler sleeps at night is 8 hours with a standard deviation of 1.2 hours. What is the sample standard deviation for a group of 100 high schoolers?
s = 0.12
500
The average number of hours a high schooler sleeps at night is 8 hours with a standard deviation of 1.2 hours. How many high schoolers would you need to survey to reduce the sample standard deviation to 0.5?
N = 5.76
500
The average number of hours a high schooler sleeps at night is 8 hours with a standard deviation of 1.2 hours. What is the probability that someone in a SAMPLE group of 9 people will sleep more than 9 hours? Report s, z-score, and probability.
s = 0.4 z = 2.5 p = 0.62%
500
The distribution of _________________ is ____________ ________________
averages approximately normal