<h3>Answer: 10</h3>
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Explanation:
We'll start off converting each mixed number into an improper fraction.
The formula to use is 
So,

And,

So the task of computing
is exactly the same as computing 
Notice how we have an 8 up top and an 8 down below. Those 8's cancel out and we're left with
. That fraction does not reduce any further.
The last step is to convert that improper fraction result to a mixed number.

Or you could note that 17/3 leads to 5 remainder 2. The 5 is the whole part and the 2 forms the numerator of the fractional part 2/3.
The value is in
form where
Therefore, A+b+c = 5+2+3 = 10
Line up the decimal points and multiply the rest like you would normally do it but drop down the decimal at the end
Answer:
Tn=a + (n-1)d
a= first term = 14
n= This is the term you're looking for... In this case... That's the 73rd term
d=Common difference (since its an AP)
d= second term - first term -- Or 3rd term - 2nd term = 23-14
d=9
T = 14 + (73-1)9
T= 14 + (72)9
T= 14 + 648
T=662.
For margin of error to be a maximum of 3:
3 = z*(SD / sqrt(n)), where z is the z-score, SD is the standard deviation and n is the sample size.
z = 1.96 for a 95% confidence interval, and we are given SD = 15.
3 = 1.96*15/sqrt(n)
sqrt(n) = 9.8
n = 96.04 ~ 96 commercials.