Answer:
The minimum sample needed to provide a margin of error of 3 or less is 52.
Step-by-step explanation:
The confidence interval for population mean (<em>μ</em>) is:

The margin of error is:

<u>Given:</u>
MOE = 3
<em>σ </em>= 11
The critical value for 95% confidence interval is: 
**Use the <em>z</em>-table for critical values.
Compute the sample size (<em>n</em>) as follows:

Thus, the minimum sample needed to provide a margin of error of 3 or less is 52.
Answer:
79.94
Step-by-step explanation:
Answer: Choice D 
Reason:
Exponential functions have the variable in the exponent.
Choice A is a polynomial, which means we can rule it out. Choice B is a log function, so we can rule it out also.
Choice C is a rational function because it is a ratio of two polynomials. This rules out choice C.
Choice D is the only function with the variable in the exponent. That is assuming you meant to say
instead of 
<span>Ok. You would set up the problem like this: 32/x=64/100 and then cross multiply; 3200=64x; divide both sides by 64; x=50. Mary has 50 customers.</span>