Question

The brain volumes ?( cm cubed cm3?) of 20 brains have a mean of 1083.9 1083.9 cm cubed cm3 and a standard deviation of 122.2 122.2 cm cubed cm3. 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 1348.3 1348.3 cm cubed cm3 be significantly? high?

Answer 1

Answer:

Range: (844.9,1333.7)

A brain volume of 1348.3 cm cubed can be considered significantly high.

Step-by-step explanation:

We are given the following information in the question:

Mean, μ = 1083.9 cm cubed

Standard Deviation, σ = 122.2 cm cubed

Range rule thumb:

• This rule state that the the range of data is four times the standard deviation of the data.

$\text{Range} = 4\times \sigma = 4\times 122.2 = 488.8$

Upper Limit:

$\mu + 2\sigma = 1089.3 + 2(122.2) = 1333.7$

Lower limit:

$\mu - 2\sigma = 1089.3 - 2(122.2) = 844.9$

Since, 1348.3 does not lie in the range (844.9,1333.7),  a brain volume of 1348.3 cm cubed can be considered significantly high.