Answer:

Step-by-step explanation:
<u>Confidence Interval</u>
When the population standard deviation
is known, the formula for a confidence interval for a population mean
is:

Where n is the sample size and z is the corresponding z-value from the standard normal distribution for the selected confidence level. The value of z for a 95% confidence interval is z=1.96. The rest of the values are

Calculating the confidence interval


Or, equivalently

Answer:
The answer is incorrect; the plus sign should be a minus sign (apex)
Step-by-step explanation:
Answer:
1. is b and 2. is c
Step-by-step explanation:
Answer:
f(30)= 75
Step-by-step explanation:
3(30)-15
90-15
75