Solution :
a). Standard error of sample mean = 

= 0.1290994
The observed mean point be 
Test statistics z = 

For the left one sided test, critical value of z to reject 
We reject
when test statics z < -1.64
b). Value of
z < -1.64



∴ we reject
when 
c). The probability of rejecting
when
,



Answer:
It would be 80.
Step-by-step explanation:
You could use the inverse operation to find the number which would be
16 x 5 = 80. You can also inverse it to find the answer.
80/5=16. Hope this helps!
The first thing we must do for this case is to define variables.
We have then:
P: pressure
A: Area of the sole of the shoe
Since the variation is inverse, we have an equation of the form:

We must find the value of k.
For this, we use the following data:
when the shoes have a sole area of 40 in ^ 2 The pressure is 4 lbs / in ^ 2
Substituting values we have:

From here, let's clear k:

Then, the equation is:
Answer:
The equation that relates these variables is: