Use technology or a z-score table to answer the question.

The number of pretzels in a bag is normally distributed with a mean of 240 pretzels and a standard deviation of 9.3 pretzels.

Approximately what percent of the bags of pretzels have between 225 and 245 pretzels?

5.4%

65.2%

70.5%

94.6%

The second choice: Approximately of the pretzel bags here will contain between 225 and 245 pretzels.

Step-by-step explanation:

This explanation uses a z-score table where each entry has two decimal places.

Let represent the mean of a normal distribution of variable . Let be the standard deviation of the distribution. The z-score for the observation would be:

.

In this question,

Calculate the z-score for and . Keep in mind that each entry in the z-score table here has two decimal places. Hence, round the results below so that each contains at least two decimal places.

.

.

The question is asking for the probability (where is between two values.) In this case, that's the same as .

Keep in mind that the probabilities on many z-table correspond to probability of (where is no greater than one value.) Therefore, apply the identity to rewrite as the difference between two probabilities:

.

Look up the z-table for and :

.

step-by-step explanation:

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step-by-step explanation: