Answer:
You need to know the miles per hour they are going to find out this answer.
Answer:
-2.25
Step-by-step explanation:
We have that the mean (m) is equal to 500, the standard deviation (sd) 20
They ask us for P (x <455)
For this, the first thing is to calculate z, which is given by the following equation:
z = (x - m) / sd
We have all these values, replacing we have:
z = (455 - 500) / (20)
z = -2.25
Answer: 554
Step-by-step explanation:
Formula we use to find the sample size :
Given : Standard deviation : 
Margin of error : E=one quarter hour = 0.25 hour
Two-tailed , Critical value use for 0.95 degree of confidence:
i.e. 
Hence, the required sample size = 554
i.e. 554 executives should be surveyed.
Answer:
X=10
Step-by-step explanation:
You can subtract 180 by 110 to get 70. Then you can do 8x+30+70=180
Add 30+70 to get 100
Subtract 100 to 180 to get 80.
8x=80
You divide 8 from both sides which leaves you with x=10.
