The brain volumes (cm3) of 20 brains have a mean of 1162.5 cm3 and a standard deviation of 126.7 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 1405.9 cm3 be significantly high?

No, the brain volume of 1405.9cm³ would not be significantly high.

Step-by-step explanation:

We would use the Empirical rule to determine the answer for this question.

The empirical rule - formula states that:

a) 68% of data falls within 1 standard deviation from the mean - that means between μ - σ and μ + σ

b) 95% of data falls within 2 standard deviations from the mean - between μ – 2σ and μ + 2σ

The question asks us to use the given standard deviation and the range rule of thumb to identify the limits separating values that are significantly low or significantly high.

The range rule of thumb tells us that the range is four times the standard deviation. So we say that the usual values will be 2 standard deviations away from the mean of the data distribution.that the values are usually within 2 standard deviations from the mean.

Hence, μ = mean =1162.5 cm³

σ = Standard deviation = 126.7 cm³

μ – 2σ

1162.5 cm³ - 2(126.7 cm³)

= 1162.5 cm³ - 253.4 cm³

= 909.1cm³

μ + 2σ

1162.5 cm³ + 2(126.7 cm³)

= 1162.5 cm³ + 253.4 cm³

= 1415.9cm³

From the calculation above, we can see that for such data, 1405.9 cm³ is within the lower limits of 909.1 cm³ and the higher limits of 1415.9 cm³. Therefore the brain volume of 1405.9 cm³ would not be significantly high.

54

step-by-step explanation:

33

step-by-step explanation: g=6