According to the empirical rule, roughly 68% of the scores fall between z = -1 and z = 1
You can use a calculator to get a more approximate answer. If you have a TI calculator, you can use the "normalcdf" function to type in normalcdf(-1,1)
1. $1.23 per pair
A dozen is 12 so you do 12x7=84
Then you do 103.32 divided by 84 which gives you 1.23
2. His error was doing 103.32 divided by 7 because he thought it was only 7 pairs but it’s 7 dozen.
1/5 is .2
.1^2 is .01
.02 is .02
So the furthest left would be the smallest number, which in this case is 0.1^2
the angle of the tower would be the coifficent