Answer:
0.2322 or 23.22 %
Step-by-step explanation:
We have to solve and find the area out of these limits
μ + 0,3 = 210 + 0,3 ⇒ 210,3 and
μ - 0,3 = 210 - 0,3 ⇒ 209.7
z(l) = ( x - 210 ) / (2.8/√84) ⇒ z(l) = - (0.3 * 9,17)/ 2.8
z (l) = - 1.195
We need to interpole from z table
1.19 ⇒ 0.1170
1.20 ⇒ 0.1151
Δ ⇒ 0.01 ⇒ 0.0019
And between our point 1,195 and 1,19 the difference is 0.005
then 0.01 ⇒ 0.0019
0.005 ⇒ ?? (x)
we find x = 0.00095
to get the area for poin z (l) - 1.195 up to final left tail is from z table
0,1170 - 0.00095 = 0.1161
And by symmetry to the right is the same
So 0.1161 * 2 = 0.2322
We find the area out of the above indicated limits the area we were looking for. This is the probability of finding shafts over and below the population mean and 0.3 inches
Step-by-step explanation:
