Answer: D
Work is shown in picture :)
Answer:
Step-by-step explanation:
In the past, mean of age of employees
i.e. 
Recently sample was taken
n = sample size = 60
Mean of sample = 45
Std dev of sample s = 16

(Right tailed test)
Since only population std deviation is known we can use t test only
Std error = 
Mean difference = 45-40 =5
Test statistic t=
df = 60
p value =0.008739
Since p < 0.05 we reject null hypothesis
The mean age has increased.
Answer:
6
Step-by-step explanation:
-3 x (8 + [-10]) =
-3 x (8 - 10) =
-3 x -2 =
6
HOpe that helps!
9. I think Austin has more rainfall.
10. Both cities have unguessable rainfalls.
11. I predict the rainfall will continue going high, then low, then high, then low.
If we solve the left side of the given equation,
1/a + 1/b = 1/c
we get an answer of,
b+a / ab = 1/c
Since ab = c, we can conclude that b + a is 1. The average of these two numbers is equal to there sum divided by 2. The answer is therefore equal to 0.5.