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Author Question: A random sample of 81 automobiles traveling on a section of an interstate showed an average speed of ... (Read 280 times)

go.lag

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on: Jun 24, 2018
A random sample of 81 automobiles traveling on a section of an interstate showed an average speed of 60 mph. The distribution of speeds of all cars on this section of highway is normally distributed, with a standard deviation of 13.5 mph. If the sample size was 25 (other factors remain unchanged), the interval for  would _____.
 a. not change
  b. become narrower
  c. become wider
  d. become zero

Question 2

The weight of items produced by a machine is normally distributed with a mean of 8 ounces and a standard deviation of 2 ounces. What is the probability that a randomly selected item will weigh between 11 and 12 ounces?
 a. .4772
  b. .4332
  c. .9104
  d. .0440


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underwood14

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Reply #1 on: Jun 24, 2018
Answer to Question 1

c

Answer to Question 2

d


go.lag

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Reply 2 on: Jun 24, 2018
YES! Correct, THANKS for helping me on my review

ttt030911

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Reply 3 on: Yesterday
Great answer, keep it coming :)

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