Answer:
107,426, bigger
Step-by-step explanation:
Given that a soccer ball manufacturer wants to estimate the mean circumference of soccer balls within 0.05 in.
Margin of error = 0.05 inches
Since population std deviation is known we can use z critical value.
(a) i.e. for 99% confidence interval
Z critical = 2.58
A minimum sample size of 107 needed.
b) 
Here minimum sample size = 426
Due to the increased variability in the population, a bigger sample size is needed to ensure the desired accuracy.
Answer:
And then the percentage between 24 and 40 would be 
Step-by-step explanation:
For this problem we have the following parameters given:
And for this case we want to find the percentage of lightbulb replacement requests numbering between 24 and 40.
From the empirical rule we know that we have 68% of the values within one deviation from the mean, 95% of the values within 2 deviations and 99.7% within 3 deviations.
We can find the number of deviations from themean for the limits with the z score formula we got:
And replacing we got:
And then the percentage between 24 and 40 would be
The domain is that Joshua is correct
Eliminate one variable at a time. We have three equations so we can solve for three variables.
(5x-y+z=4)-5(x+2y-z=5)=-11y+6z=-21
-2(x+2y-z=5)+(2x+3y-3z=5)=-y-z=-5
Now using the two yz equations above to cancel out z
(-11y+6z=-21)+6(-y-z=-5)=-17y=-51
-17y=-51 divide both sides by -17
y=3, making -y-z=-5 become:
-3-z=-5, z=2, making <span>5x-y+z=4 become:
5x-3+2=4
5x-1=4
5x=5
x=1
So the solution to the system of equations, (x,y,z) is (1,3,2)</span>
The mean of the data set is 14.4
