Question

h² = 1 and that gene frequencies are known.

Assume you have 3 beef cows whose birth weights were as follows: A = 65 lbs, B = 75 lbs and C = 85 lbs. Your employer wants to breed only those cows which are more than 1 Standard Deviation above the population mean. If the population mean for birth weights, m_BW = 70 lbs, and the variance for birth weights, s²_BW = 64 lbs², how many of the cows should you select for breeding? Which ones specifically?

hint for this question-

1. m_BW + 1 S.D. =

Answer 1

One standard deviation above the mean is the number a distance of one standard deviation to the right of the mean.

If we had a mean of and a standard deviation of then ( + ) would be one standard deviation above the mean.

Here given

Population mean for birth weights, mBW = 70 lbs, and the variance for birth weights, s2BW = 64 lbs2

Thus = 70 and = = 8

Thus = 70   and   = 8 .

We had mean of 70 and a standard deviation of 8 then (70+8) = 78 would be one standard deviation above the population mean. ( i.e mBW + 1 S.D. = 70 + 8 = 78 )

Now    ,    A = 65 lbs, B = 75 lbs and C = 85 lbs

And we wants to breed only those cows which are more than 1 Standard Deviation above the population mean.   Thus we will select only those cow whose birth weights are above 78

Here   C= 85 is only one cow whose birth weight is above one standard deviation above the population mean 78

Thus we will select only one cow for breeding .

It will be cow " C " with weight 85lbs.