Answer:
the right answer is -5 (B)
Step-by-step explanation:
-(-5) +5(-5+2)
5 + -15 = -10
Answer: C. 12.5
Step-by-step explanation:
Given : A manufacturer of new light bulbs claims the average lifetime of its long-life bulb is more than 4000 hours.
Population mean : 
Sample size : n= 100
Sample mean : 
Standard deviation: 
The value of test-statistic is given by :-

Hence, the value of the test statistic for this problem is 12.5.
Answer:
-9 minus -3
Step-by-step explanation:
-9 - (-3) = -9 + 3 = -6
Subtract and keep the sign of the bigger number.