Empirical Rule
Z-Scores
Probabilities
Misc.
100
The percentage of data that falls within one standard deviation of the mean.
What is 68%
100
The z-score corresponding to an SAT score of 630 when the mean score is 500 and the standard deviation is 100.
What is 1.3
100
The probability of randomly selecting a member of a normally distributed population with a value less than the mean of the population.
What is .5
100
The greek symbol used to represent standard deviation.
What is sigma (lower case)
200
The percent of data that is within 2 standard deviations of the mean.
What is 95%
200
The sign of the z-score of any data point that falls BELOW the mean.
What is negative.
200
US men in the age group of 20-29 have heights that are normally distributed with a mean of 69.6 inches and a standard deviation of 3.0 inches. This is the probability of randomly selecting a man in this age group whose height is more than 72 inches.
What is .21
200
The z score tells you how many of these a data point is from the mean.
What is standard deviation
300
The percentage of dat that falls within 3 standard deviations of the mean.
What is 99.7%
300
The z score of a data point that is equal to the mean of the data.
What is 0
300
US men in the age group of 20-29 have heights that are normally distributed with a mean of 69.6 inches and a standard deviation of 3.0 inches. This is the probability of randomly selecting a man in this age group whose height is between 66 and 72 inches.
What is .67
300
Why is it important to sketch a picture of a normal curve before finding percentages under the curve?
What is to make sure you have the correct percent. (Might need to subtract from 1)
400
The percent of data that lies outside one standard deviation of the mean.
What is 32%
400
The z score of a data point that is equal to the mean of the data.
What is .84
400
The weights of adult male beagles are normally distributed, with a mean of 25 pounds and a standard deviation of 3 pounds. This is the probability of randomly selected an adult male beagle whose weight is less than 23 pounds.
What is .25
500
The percentage of data that lies between the mean and one standard deviation above the mean.
What is 34%
500
The area under the standard normal curve between the z-scores of -2 and 1.
What is .815
500
The weights of adult male beagles are normally distributed, with a mean of 25 pounds and a standard deviation of 3 pounds. This is the probability of randomly selected an adult male beagle whose weight is less than 22 pounds or greater than 28 pounds.
What is .32
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