Answer:
Step-by-step explanation:
given that certain tubes manufactured by a company have a mean lifetime of 800 hours and a standard deviation of 60 hours.
Sample size n =16
Std error of sample mean = 
x bar follows N(800, 15)
the probability that a random sample of 16 tubes taken from the group will have a mean lifetime
(a) between 790 and 810 hours,
=
(b) less than 785 hours

, (c) more than 820 hours,

(d) between 770 and 830 hours
=
Answer:
Step-by-step explanation:
4. 10x + 30 = 90
10x = 60
x = 6
complementary
5. 4x + 40 + 3x = 180
7x + 40 = 180
7x = 140
x = 20
supplementary
First you want to find how many words she types per hour.
There are 60 minutes in 1 hour.
So multiply 70 words/min times 60 min/ 1 hr to cancel out the minutes.
You will get 4200 words / hr
Then multiply 4200 by 4 and 5
use * as multiplication symbol
4200 words/hr * 4 = 16,800 words/hr
4200 words/hr * 5 = 21,000 words/hr
She will type 16,800 - 21,000 words/hr
So Your answer is going to be letter G
Answer:-98.4+18.8
Step-by-step explanation: