Questions: 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 21.3 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 less than (Round to one decimal place as needed.) B. Test scores that are greater than (Round to one decimal place as needed.) C. Test scores that are between and (Round to one decimal place as needed. Use ascending order.)

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 21.3 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 less than (Round to one decimal place as needed.) B. Test scores that are greater than (Round to one decimal place as needed.) C. Test scores that are between and (Round to one decimal place as needed. Use ascending order.)

Transcript text: 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 21.3 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 less than $\square$ (Round to one decimal place as needed.) B. Test scores that are greater than $\square$ (Round to one decimal place as needed.) C. Test scores that are between $\square$ and $\square$ (Round to one decimal place as needed. Use ascending order.)

Solution

Solution Steps

Step 1: Calculate Significantly Low and High Thresholds

Given:

Mean test score, $\mu = 21.3$
Standard deviation, $\sigma = 4.9$

Using the range rule of thumb, we calculate the significantly low and high thresholds as follows:

Significantly low threshold: $\mu - 2\sigma$
Significantly high threshold: $\mu + 2\sigma$

Step 2: Compute the Values

Substitute the given values into the formulas:

Significantly low threshold: $21.3 - 2 \times 4.9 = 21.3 - 9.8 = 11.5$
Significantly high threshold: $21.3 + 2 \times 4.9 = 21.3 + 9.8 = 31.1$

Final Answer

Based on the calculations:

Test scores that are significantly low are those less than $11.5$ .
Test scores that are significantly high are those greater than $31.1$ .
Test scores that are neither significantly low nor significantly high are those between $11.5$ and $31.1$ .