Standard Deviation AP Statistics

The average points scored in an NBA game is 220 with a standard deviation of 18. Determine the likelihood that a random sample of 40 games would have a mean less than 225.

• Cannot be determined

• 0.9605

• 0.6094

• 0.8563

Which of the following is the central limit theorem used for?

• The standard deviation of the distribution of sample means is found by dividing the population standard deviation by n.

• The distribution of sample means will be approximately normal if the sample size is at least 30.

• The distribution of sample proportions is approximately normal if both np and n(1 - p) are greater than or equal to 10.

• As sample size increases, variability decreases.

The average points scored in an NBA game is 220 with a standard deviation of 18. Determine the likelihood that a sample of 10 games would have a mean greater than 230.

• 0.0395

• 0.0817

• 0.2893

• Cannot be determined

The weight of adult male grizzly bears living in the wild in the continental United States is approximately normally distributed with a mean of 500 pounds and a standard deviation of 50 pounds. The weight of adult female grizzly bears is approximately normally distributed with a mean of 300 pounds and a standard deviation of 40 pounds. Approximately, what would be the weight of a female grizzly bear with the same standardized score (z-score) as a male grizzly bear with a weight of 530 pounds?

• 276 pounds

• 324 pounds

• 330 pounds

• 340 pounds

• 530 pounds

The commuting time for a student to travel from home to a college campus is normally distributed with a mean of 30 minutes and a standard deviation of 5 minutes. If the student leaves home at 8:25 am, what is the probability that the student will arrive at the college campus later than 9 am?

• 0.16

• 0.32

• 0.50

• 0.84

• 1.00

Of the following dotplots, which represents the set of data that has the greatest standard deviation?

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The standard deviation about the least squares line is roughly the typical amount by which an observation deviates from the least squares line.

• True

• False

If r = 1 , the standard deviation of y is equal to the standard deviation of the residuals.

• True

• False