Answer:
The bulbs should be replaced each 1436.9 hours.
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean 
and standard deviation 
, the zscore of a measure X is given by:
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:
How often should the bulbs be replaced so that no more than 1% burn out between replacement periods?
This is the first percentile of hours. So it is X when Z has a pvalue of 0.01.
So it is X when Z = -2.33.
The bulbs should be replaced each 1436.9 hours.
Answer:
I think the answer is D. On average, boys saw the movie more than girls.
Do great on the test! ~ :)
Answer:
60°
Step-by-step explanation:
measure of angle ACB = 180-135= 45
then the required angle = 180-(45+75) = 60°
I hope that was helpful
Answer:
x= 2/5, -2, 2
Step-by-step explanation:
Answer:
C. Gregory's graph is incorrect because it shows 2 inches of growth for each week, when it should show 0.75 inches of growth each week
Step-by-step explanation:
Given that the plant grows 1.5 inches (y) every 2 weeks (x), it means that:
Rate of change = y/x = 1.5/2 = 0.75 inches per week
The graph he should create should have a rate of change of 0.75. that is, it should show 0.75 inches growth for every week.
The graph shown above has a rate of change of 2 inches per week.
Thus, the graph is incorrect. It should be showing 0.75 inches of growth per week instead of 2 inches.
