Answer:
the answer is D
Step-by-step explanation:
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
=
A(0,-1)
B(3√3/3, 2)
Slope of AB = (y₂ - y₁)/(x₂-x₁)
Slope = (2-1)/(√3/3 , -0)
Slope = 1/√3/3 = 1/√3 = √3/3
OR SLOPE = tan(a°) = √3/3 and a° = 30°