Amy has set aside $150 a month for her cell phone bill. The cost for a monthly cell phone plan is a $65 access fee plus $20 per
1 answer:
You might be interested in
Answer:
The 95% confidence interval for the population mean is between 61.5 and 68.5.
Step-by-step explanation:
We have that to find our level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Ztable as such z has a pvalue of .
So it is z with a pvalue of , so
Now, find M as such
In which is the standard deviation of the population and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 65 - 3.5 = 61.5
The upper end of the interval is the sample mean added to M. So it is 65 + 3.5 = 68.5
The 95% confidence interval for the population mean is between 61.5 and 68.5.
Answer:
$1,061.76
Step-by-step explanation:
(refer to attached handout)
For compound interest, you are given:
A = ? (need to find)
P = $1000
r = 3% = 0.03
n = compounded monthly = 12 times per year
t = 2 years
(substituting this into the formula)
A = P [ 1 + (r/n) ] ^(nt)
A = 1000 [ 1 + (0.03/12) ] ^[(12)(2)]
A = 1000 [ 1 + 0.0025 ] ^24
A = 1000 [ 1.0025 ] ^24
A = 1,061.76
