Answer:
a) 
And rounded up we have that n=4906
b) For this case since we don't have prior info we need to use as estimatro for the proportion 
And rounded up we have that n=6724
Step-by-step explanation:
We need to remember that the confidence interval for the true proportion is given by :
Part a
The estimated proportion for this case is 
Our interval is at 90% of confidence, and the significance level is given by 
and 
. The critical values for this case are:
The margin of error for the proportion interval is given by this formula:
(a)
The margin of error desired is given 
and we are interested in order to find the value of n, if we solve n from equation (a) we got:
(b)
Replacing we got:
And rounded up we have that n=4906
Part b
For this case since we don't have prior info we need to use as estimatro for the proportion
And rounded up we have that n=6724
To convert a decimal into scientific notation, move the decimal point until you get to the left of the first non-zero integer. The number of places the decimal point moves is the power of the exponent, because each movement represents a "power of 10".
Simplified expression for total amount spent is 10(2.05 + m)
Step-by-step explanation:
- Step 1: Write expression for expense on joining cooking club for m months.
Expense = 8.50 + 6.25 × m
- Step 2: Write expression for expense on joining movie club for m months.
Expense = 12 + 3.75 × m
- Step 3: Calculate the total amount spent on both clubs
Total Amount = 8.50 + 6.25m + 12 + 3.75m = 20.5 + 10m = 10(2.05 + m)
