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What is the probability a subscriber will spend at least 1 hour reading The Wall Street Journal if the average time spent is 49 minutes with a standard deviation of 16 minutes?

a) 0.3085
b) 0.6915
c) 0.8413
d) 0.1587

User Jenelly
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8.3k points

1 Answer

5 votes

Final answer:

The probability of a subscriber spending at least 1 hour reading The Wall Street Journal is found by calculating a Z-score and using the standard normal distribution table. The Z-score for 60 minutes is 0.6875, and the corresponding probability is 0.2546. The correct answer is 1 - 0.2546, which is 0.7454, and this is not listed in the provided options.

Step-by-step explanation:

The probability that a subscriber will spend at least 1 hour (or 60 minutes) reading The Wall Street Journal can be found using the Z-score formula, which is Z = (X - μ) / σ, where X is the value for which we want to find the probability, μ is the mean, and σ is the standard deviation.

The mean time spent (μ) is given as 49 minutes, and the standard deviation (σ) is 16 minutes. To find the probability for at least 1 hour, we need to calculate the Z-score for 60 minutes.

Z = (60 - 49) / 16 = 11 / 16 = 0.6875

Using the standard normal distribution table, we look up the probability for Z = 0.6875, which gives us a probability of 0.2546. However, since we want the probability of spending at least 1 hour, we need to subtract this value from 1 (as the table gives us the probability of being less than a certain value).

The correct probability is 1 - 0.2546 = 0.7454.

This is not one of the options provided, so it seems there may have been an error in the listed choices or the calculation process.

User Kewlashu
by
7.8k points
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