The brain volumes \( \left(\mathrm{cm}^{3}\right) \) of 20 brains have a mean of \( 1069.3 \mathrm{~cm}^{3} \) and a standard deviation of \( 123.7 \mathrm{~cm}^{3} \). Use the given standard deviation and the range rule of thumb to identify the limits separating values that are significantly low or significantly high. For such data, would a brain volume of \( 1356.7 \mathrm{~cm}^{3} \) be significantly high?
Significantly low values are \( \square \mathrm{cm}^{3} \) or lower.
(Type an integer or a decimal. Do not round.)
Answer
Determine whether 1356.7 is significantly high by comparing it to L2.
Step 1 ：Find the lower limit L1 and upper limit L2 of significant values: L1 = \( \mu - 2\sigma \) and L2 = \( \mu + 2\sigma \)
Step 2 ：Calculate L1 and L2: L1 = \( 1069.3 - 2(123.7) \) and L2 = \( 1069.3 + 2(123.7) \)
Step 3 ：Determine whether 1356.7 is significantly high by comparing it to L2.
