Answer:

Step-by-step explanation:
So we have the equation:

Let's let u be equal to x². So:

Factor:

Zero Product Property:

Subtract:

Replace:

Take square root:

Simplify:

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.
- 5/12 + ( - 1/4) =
Adding two negatives results in a negative
-1/4 = -3/12
-3/12 + -5/12 = -8/12
-8/12 + 3/12 < Subtract and take the sign of the BIGGER number.
8 - 3 = 5
- 5/12
Answer: - 5/12
Answer:
The answer is 6 ratio because when you divide these two number then the anwer is 6