Answer:
The bulbs should be replaced each 1060.5 days.
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, that is, the value of X when Z has a pvalue of 0.01. So X when Z = -2.325.
The bulbs should be replaced each 1060.5 days.
X-4y=-12
4x-y=12
eliminate y's
multily 2nd equaiton by -4 and add to top one
x-4y=-12
<u>-16x+4y=-48 +
</u>-15x+0y=-60
-15x=-60
divide both sides by -15
x=4
sub back
x-4y=-12
4-4y=-12
minus 4 both sides
-4y=-16
divide both sides by -4
y=4
x=4
y=4
(x,y)
(4,4)<u>
</u>
the only statement that is true is the one in option D.
"Bar graphs are used to represent data that is discrete".
<h3>Which of the statements are true regarding dot plots, bar graphs, and histograms?</h3>
Dot plots, bar graphs, and histograms are used to repersent graphically data sets.
Thus, what these graphs do represent are populations in a data set with a given property.
Remember that data is usually discrete, so we usually use dot plots and bar graphs to represent discrete data.
Histograms show distributions of numerical data (it can be used for continuous or discrete data).
With all that in mind, we conclude that the only statement that is true is the one in option D.
"Bar graphs are used to represent data that is discrete".
If you want to learn more about data sets:
brainly.com/question/3514929
#SPJ1
Answer:
tan (C) = 2.05
Step-by-step explanation:
Given:
A right angled triangle CDE right angled at ∠D.
Side CD = 39
Side DE = 80
Side CE = 89
We know, from trigonometric ratios that, the tangent of any angle is equal to the ratio of the opposite side to the angle and the adjacent side of the angle.
Therefore, tangent of angle C is given as:
Plug in the given values and solve for angle C.This gives,
Therefore, the measure of tangent of angle C is 2.05.
