Question

use the range rule of thumb to identify the values that are significantly low, the values that are significantly high, and the values that are neither significantly low nor significantly high. a test is used to assess readiness for college. in a recent year, the mean test score was 19.4 and the standard deviation was 4.9. identify the test scores that are significantly low or significantly high. what test scores are significantly low? select the correct answer below and fill in the answer box(es) to complete your choice. a. test scores that are greater than (round to one decimal place as needed.) b. test scores that are between and (round to one decimal place as needed. use ascending order.) c. test scores that are less than (round to one decimal place as needed.)

Explanation:

Step1: Recall the range rule of thumb formula

The range rule of thumb states that values are significantly low if they are less than \(\mu - 2\sigma\), significantly high if they are greater than \(\mu+ 2\sigma\), and neither if they are between \(\mu - 2\sigma\) and \(\mu + 2\sigma\). Here, \(\mu = 19.4\) (mean) and \(\sigma=4.9\) (standard deviation).

Step2: Calculate \(\mu - 2\sigma\)

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Step3: Calculate \(\mu + 2\sigma\)

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Since we are asked for significantly low scores (using the formula for significantly low: \(x<\mu - 2\sigma\))

Answer:

C. Test scores that are less than \(9.6\)