Answer:
0.15866 is the probability of the average fracture strength of selected 100 pieces of glasses that of exceed 14.3.
Step-by-step explanation:
Given that, the strength of a tempered(x) a glass has average 14.1 and has standard deviation 2.
, 
n=number of selected pieces= 100.
The probability that the average fracture strength of 100 pieces of this glass exceed 14.3 is



= 1 - 0.84134
=0.15866.
In this case u can’t use the distributive property. U just multiple whats in the parenthesis (39•5)=195 and that’s ur answer.
Let’s say if the problem said 5(2+1) u can’t use the distributive property bc u have to do what’s in the parentheses first. 5(3)=15
But If u had a problem like 2(4x+6) then u can use the distributive property. This is bc u can’t add 4x+6 bc they aren’t like terms. So u multiple the 2 by 4x which is 8x and the 2 by 6 which is 12 then ur answer would be : 8x+12
We would need a sample size of 560.
We first calculate the z-score associated. with this level of confidence:
Convert 95% to a decimal: 95% = 95/100 = 0.95
Subtract from 1: 1-0.95 = 0.05
Divide by 2: 0.05/2 = 0.025
Subtract from 1: 1-0.025 = 0.975
Using a z-table (http://www.z-table.com) we see that this is associated with a z-score of 1.96.
The margin of error, ME, is given by:

We want ME to be 4%; 4% = 4/100 = 0.04. Substituting this into our equation, as well as our proportion and z-score,
The equation would be 2x+3 so when you plug it in it's 2(-2)+3 which simplify to -4+3 which is -1