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 19.7 with a standard deviation was 4.5. 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.)
what test scores are significantly high? 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 between □ and □ (round to one decimal place as needed. use ascending order.)
c. test scores that are greater than □ (round to one decimal place as needed.)

Explanation:

Step1: Recall range - rule - of - thumb

According to the range - rule - of - thumb, significant low values are $\mu - 2\sigma$ and below, and significant high values are $\mu+2\sigma$ and above, where $\mu$ is the mean and $\sigma$ is the standard deviation.

Step2: Calculate significant low value

Given $\mu = 107$ and $\sigma = 4.5$. The significant low value is $\mu - 2\sigma=107-2\times4.5=107 - 9 = 98.0$.

Step3: Calculate significant high value

The significant high value is $\mu + 2\sigma=107 + 2\times4.5=107+9 = 116.0$.

Answer:

What test scores are significantly low?
C. Test scores that are less than 98.0
What test scores are significantly high?
C. Test scores that are greater than 116.0