Answer:
4.5 i think
Step-by-step explanation:
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:
y = 3x -4
Step-by-step explanation:
The slope-intercept equation looks like this:
. Where m is the slope of the function and b is the y-coordinate of the vertical intercept (where the function crosses the y-axis). Let's apply the formula:



4 , divide the x by the y to find a constant
You'd first have to find out what percentage of people would be 30 out of 100%