Answer:
Step-by-step explanation:
Given that confidence level is 95% and sample mean is within 10 minutes of the population mean. i.e. margin of error = 10
Std deviation of population= 211 minutes
Margin of error = Z critical * std error
Std error = sigma/sq rt n = 
Hence we have
\frac{211}{\sqrt{n} }
The minimum sample size is 1710
a) There may not be 1,809 computer users to survey
Answer:

Step-by-step explanation:

Answer:
-7
Step-by-step explanation:
-5+|-11|+-13
-5+11+-13
6+-13
= -7
Answer:
b=2A/h-a
Step-by-step explanation:
A=1/2h(a+b)
a+b=A/(1/2h)
a+b=A/(h/2)
a+b=(A/1)(2/h)
a+b=2A/h
b=2A/h-a