Question

The length of timber cuts are normally distributed with a mean of 95 inches and a standard deviation of 0.52 inches. In a random sample of 30 boards, what is the probability that the mean of the sample will be between 94.7 inches and 95.3 inches?

0.002

0.950

0.436

0.998

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Question 182 pts

The Dow Jones Industrial Average has had a mean gain of 432 pear year with a standard deviation of 722. A random sample of 40 years is selected. What is the probability that the mean gain for the sample was between 200 and 500?

0.703

0.297

0.164

0.836

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Question 192 pts

Of all the companies on the New York Stock Exchange, profits are normally distributed with a mean of $6.54 million and a standard deviation of $10.45 million. In a random sample of 73 companies from the NYSE, what is the probability that the mean profit for the sample was between -2.9 million and 4.5 million?

0.048

0.239

0.477

0.052

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Question 202 pts

Doing research for insurance rates, it is found that those aged 30 to 49 drive an average of 38.7 miles per day with a standard deviation of 6.7 miles. These distances are normally distributed. If a group of 60 drivers in that age group are randomly selected, what is the probability that the mean distance traveled each day is between 38.0 miles and 39.9 miles?

0.708

0.780

0.113

0.199

The weights of bags of peas are normally distributed with a mean of 13.50 ounces and a standard deviation of 1.06 ounces. Bags in the upper 4% are too heavy and must be repackaged. What is the most that bag and weigh and not need to be repackaged?

15.36 ounces

11.64 ounces

11.76 ounces

15.24 ounces

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Question 132 pts

A stock’s price fluctuations are approximately normally distributed with a mean of $29.51 and a standard deviation of $3.87. You decide to sell whenever the price reaches its highest 20% of values. What is the highest value you would still hold the stock?

$32.38

$25.25

$31.77

$24.50

Answer 1