Standard algorithm i think
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We have been given that the distribution of the number of daily requests is bell-shaped and has a mean of 38 and a standard deviation of 6. We are asked to find the approximate percentage of lightbulb replacement requests numbering between 38 and 56.
First of all, we will find z-score corresponding to 38 and 56.


Now we will find z-score corresponding to 56.

We know that according to Empirical rule approximately 68% data lies with-in standard deviation of mean, approximately 95% data lies within 2 standard deviation of mean and approximately 99.7% data lies within 3 standard deviation of mean that is
.
We can see that data point 38 is at mean as it's z-score is 0 and z-score of 56 is 3. This means that 56 is 3 standard deviation above mean.
We know that mean is at center of normal distribution curve. So to find percentage of data points 3 SD above mean, we will divide 99.7% by 2.

Therefore, approximately
of lightbulb replacement requests numbering between 38 and 56.
<h3>
<u>Answer:</u></h3>

<h3>
<u>Step-by-step explanation:</u></h3>
Given function to us is :-
And we , need to write the function a a product of linear factor by grouping or using the x method or a combination of both . So let's factorise this ,
I have also attached the graph of x²-9.
<h3>
<u>Hence </u><u>option</u><u> </u><u>A</u><u> </u><u>is</u><u> </u><u>corr</u><u>ect</u><u> </u><u>.</u></h3>
Since
are in arithmetic progression,




and since
are in geometric progression,




Recall that


It follows that

so the left side is

Also recall that

so that the right side is

Solve for
.

Now, the numerator increases more slowly than the denominator, since


and for
,

This means we only need to check if the claim is true for any
.
doesn't work, since that makes
.
If
, then

If
, then

If
, then

There is only one value for which the claim is true,
.
Just keep adding 5 to the number