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Beginning teachers' salaries are approximately bell-shaped with a mean of $51,740 with a standard deviation of $4,630. a) What percentage of beginning salaries will be between $37,850 and $65,630? b) 95% of the beginning salaries will be between what 2 values?

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Answer:

Therefore, 95% of beginning salaries will fall between $42,032.40 and $60,447.60.

Explanation:

a) To find the percentage of beginning salaries between $37,850 and $65,630, we need to standardize the values using the z-score formula:

z1 = (37850 - 51740) / 4630 = -3.00

z2 = (65630 - 51740) / 4630 = 3.00

Using a standard normal distribution table or calculator, we can find the area under the curve between -3.00 and 3.00 to be approximately 99.7%. Therefore, approximately 99.7% of beginning salaries will be between $37,850 and $65,630.

b) To find the two values between which 95% of beginning salaries will fall, we need to find the z-scores that correspond to the 2.5th and 97.5th percentiles of the standard normal distribution. These z-scores are approximately -1.96 and 1.96, respectively.

We can use these z-scores to find the corresponding salary values:

z1 = (x1 - 51740) / 4630 = -1.96

x1 = -1.96 * 4630 + 51740 = $42,032.40

z2 = (x2 - 51740) / 4630 = 1.96

x2 = 1.96 * 4630 + 51740 = $60,447.60

Therefore, 95% of beginning salaries will fall between $42,032.40 and $60,447.60.

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