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.

$z=\frac{x-\mu}{\sigma}$

$z=\frac{38-38}{6}=\frac{0}{6}=0$

Now we will find z-score corresponding to 56.

$z=\frac{56-38}{6}=\frac{18}{6}=3$

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 $-3\sigma\text{ to }3\sigma$ .

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.

$\frac{99.7\%}{2}=49.85\%$

Therefore, approximately $49.85\%$ of lightbulb replacement requests numbering between 38 and 56.

6 0

3 years ago

Ive been having this question for a while "what do you use first PEMDAS or Order of Operations". Well you might say it doesn't m

IgorLugansk [536]

Answer:

Order of Operations was aught at a younger age for those just grasping the idea of multiplication and division. Exposing PEMDAS at a young age would confuse them too much, hence the order of operation groups, addition/subtraction and multiplication/division. So for the second example problem, PEMDAS would be correct because it does involve you to use parentheses as well as exponents to solve for. Very easy to mix up between order of operations and PEMDAS, but just look at it as if Order of operations is a beginner level of PEMDAS.

Step-by-step explanation:

5 0

3 years ago

the diameter of your bicycle wheel is 34 inches.What is its radius?How far will you move in one turn if your wheel?What is the d

gulaghasi [49]

Answer:

Step-by-step explanation:

The radius of a circle is always half the radius.

Thus, in this case, the radius is (1/2)(34 in) = 17 in.

The "how far" question is answerable by finding the circumference of the wheel. The circumference, C, is found by calculating C = πd, where d is the diameter of the circle in question.

Here, C = (34 in)π, which comes out to 106.81 inches. The bike will move 106.81 inches forward if the wheel turns once.

If the wheel turns 5 times, the total distance traveled is 5 times the circumference, or 5(106.81 in) = 534.07 in.

6 0

3 years ago