Begin making a chart of each car per hour. answer: 2hours
P(sugar cookie)= 8/28=4/14
P(peanut butter cookie)=5/27
Solution :




= 178 x 0.48
= 85.44
≈ 85

= 427 x 0.38
= 162.26
≈ 162
a). Yes, the sample sizes are large enough to use the large sample confidence interval so as to estimate the difference in the population proportions.
Let 
Where the
the age
group and the 2 - subscript indicates the age
group.
Since 

are all at least 10, the sample sizes are large enough to use the large sample confidence interval.


= 0.409421


= 1 - 0.4094
= 0.5906
b). 90% confidence interval is







c). Zero is not included in the confidence interval. Answer is no. The difference in the two population proportion are different from each other.
To calculate percentage increase, use the following method:
First, Work out the difference (increase) between the two numbers you are comparing.
Increase = New Number - Original Number
Now, divide the increase by the original number and multiply the answer by 100.
% increase = Increase ÷ Original Number × 100.
Also, If your answer is a negative number it is a percentage decrease.
To calculate percentage decrease, use this method:
First, Work out the difference (decrease) between the two numbers you are comparing.
Decrease = Original Number - New Number
Then, divide the decrease by the original number and multiply the answer by 100.
% Decrease = Decrease ÷ Original Number × 100
Also, If your answer is a negative number then it is a percentage increase.
<span>If you wish to calculate the percentage increase or decrease of several numbers then I recommend using the first formula. Positive values indicate a percentage increase whereas negative values indicate percentage decrease.</span>