Statistics normal dispution probality z table

Question

Problem 4.

What is the probability that the shopper will be in the supermarket between 31 and 58 minutes? Mean 43 minutes Standard deviation 12 min

Hint: Convert the normal distribution X to Standard normal using Z formula Z=(X-μ)/σ and then look the Z-values from the table and then find the probability.

Please help very confused converting x to z and when to minus 1 help

How do write the answer is which way help me have no idea hiw they want like tgiss trying to learn ugh

p(31<x<58)=p(-1<z<1.25)=p(z<-1)=0.8944-0.1587=0.7357

help get finial answer like this format 

Answer 1

The process for finding the probability of a normally distributed variable is to find the area under the standard normal curve based on the z variable. You text has a table that gives the area to the right or left of a given z value. For an area with left-hand limit z₁ and right hand limit z₂ Pr(z₁ < z < z₂) = Area(from z₁ to z₂) = Table(z₂ - z₁) if the table gives areas to the left of z.

Evaluating the z limits involves plugging into the formula for z = (x-μ)/σ where μ is the mean,σ is the standard deviation, and x is the variable that you are concerned with.

z₁ = (31-43)/12 = -1 and z₂ = (58-43)/12 = 1.25

This explains the 2nd statement. The third statement is not true. It should be p(1.25) - p(-1)

table values for z = 1.25 : .8944 to left z = -1: .1587 to left

and that is why the final answer is .8944 - .1857

z tables vary: If you get a table that gives you area to the right... 1- area = area to the left

Some tables give the area from the middle to the + z value... here add .5 to the area to get area to the left.

Please consider a tutor.