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The weights of ice cream cartons produced by a manufacturer are normally distributed with a mean weight of 10 ounces and a standard deviation of 0.5 ounces. You randomly select 25 cartons. What is the probability that their mean weight is greater than 10.21 ounces?

A. 0.3085
B. 0.6915
C. 0.6910
D. 0.3080

User Svitlana
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1 Answer

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Final answer:

To find the probability that the mean weight of the randomly selected cartons is greater than 10.21 ounces, calculate the z-score and use the z-table to find the probability. The probability is approximately 0.0085. None of the option is correct

Step-by-step explanation:

To find the probability that the mean weight of the randomly selected cartons is greater than 10.21 ounces, we need to calculate the z-score and then use the z-table to find the corresponding probability.

The z-score is calculated using the formula: z = (X - mu) / (sigma / sqrt(n)), where X is the sample mean, mu is the population mean, sigma is the population standard deviation, and n is the sample size.

In this case, X = 10.21 ounces, mu = 10 ounces, sigma = 0.5 ounces, and n = 25 (sample size).

Plugging these values into the formula, we get: z = (10.21 - 10) / (0.5 / √(25)) = 2.42.

Using the z-table, we find that the probability corresponding to a z-score of 2.42 is approximately 0.9915.

Therefore, the probability that the mean weight of the 25 cartons is greater than 10.21 ounces is approximately 1 - 0.9915 = 0.0085.

None of the option is correct

User Matt Brandt
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