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
=
The answer would be rounded by 7
Answer:
6 years
Step-by-step explanation:
t=2250/375
t=6
Hence time of the loan will be 6 years
X^2-7x+38=5x+3
x^2-7x+38-5x-3=5x+3-5x-3
x^2-12x+35=0
Factoring:
(x-5)(x-7)=0
Two solutions:
x-5=0→x-5+5=0+5→x=5
x-7=0→x-7+7=0+7→x=7
Answer: x=5 and x=7
Answer: Options B. 7 and D. 5