Answer: C . 
and 
Step-by-step explanation:
Definition:
Null hypothesis
is a statement about the population parameter according to the objective raised by the researcher . It contains '=' , '≤' and '≥' signs.
Alternative hypothesis
is also a statement about the population parameter but against null hypothesis . It contains '≠' , '<' and '>' signs.
Let 
be the average customer waiting time for the population.
Given : The average customer waiting time at a fast food restaurant has been 7.5 minutes.
Objective of test : After using new system , the average customer waiting time is at least 7.5 or less than 7.5.
Then, the null and alternative hypothesis for this scenario will be :
Answer:
92 dB
Step-by-step explanation:
Use the mean formula, mean = sum of elements / number of elements.
Since it is a 8 hour work day, there are 8 elements.
mean = sum of elements / number of elements
mean = (98 + 98 + 98 + 98 + 98 + 82 + 82 + 82) / 8
mean = 736 / 8
mean = 92
So, the average noise level is 92 dB
Answer:
third side = 9
Step-by-step explanation:
Using Pythagoras' identity on the right triangle.
The square on the hypotenuse is equal to the sum of the squares on the other 2 sides.
let the third side be x, then
x² + 40² = 41², that is
x² + 1600 = 1681 ( subtract 1600 from both sides )
x² = 81 ( take the square root of both sides )
x = 
= 9
The third side is 9
