HELP ME WITH THIS WORK PLEASEEE

What’s the answer and how do I solve it?

Levart [38]

A solution is where the graph crosses the x axis (when y=0). Since the graph never touched the x axis, there is no solution.

6 0

3 years ago

Below is a square which had a rectangle measuring 4 by 3 cm removed find the area of the shaded part

posledela

What is the area of a circle with radius 7.5

7 0

3 years ago

All 423 Wisconsin public schools were all given a rating by the Wisconsin Department ofPublic Instruction based on several varia

Blizzard [7]

Answer:

$z = \frac{\bar X -\mu}{\sigma_{\bar X}}= \frac{70.9-71.5}{0.77}=-0.779$

From this result we can conclude that the value of 70.9 is 0.78 deviation below the true mean of 71.5 and that can be considered as unusual. If we conduct a hypothesis test or a confidence interval we will see that we have enough evidence to conclude that the true mean is not significantly different from 71.5.

Step-by-step explanation:

For this case from all the population we know that the population mean and deviation are:

$\mu = 71.5,\sigma = 4.87$

And we take a random sample of size n =40 and we got a sample mean calculated with the following formula:

$\bar X =\frac{\sum_{i=1}^n X_i}{n}= \frac{\sum_{i=1}^{40} X_i}{40}=70.9$

And we want to test if this value is unusually low.

Since the sample size is large n>30 we can use the central limit theorem who says that the distribution for the sample mean is given by:

$\bar X \sim N (\mu , \frac{\sigma}{\sqrt{n}})$

And on this case if we replace the values that we have we got:

$\bar X \sim N (\mu_{\bar X}=71.5,\sigma_{\bar X}= \frac{\sigma}{\sqrt{n}}=\frac{4.87}{\sqrt{40}}=0.77)$

For this case we can calculate how many deviations above or below is our calculated value from the sample of size 40, using the z score given by:

$z = \frac{\bar X -\mu}{\sigma_{\bar X}}= \frac{70.9-71.5}{0.77}=-0.779$

From this result we can conclude that the value of 70.9 is 0.78 deviation below the true mean of 71.5 and that can be considered as unusual. If we conduct a hypothesis test or a confidence interval we will see that we have enough evidence to conclude that the true mean is not significantly different from 71.5.

3 0

3 years ago

Use summation notation to write the series -1 + 2 + 5 + 8 + 11... for 10 terms, then evaluate the sum.

garri49 [273]

Answer:

-1 + 2 + 5 + 8 + 11 + 14 + 17 + 20 + 23 + 26

10 terms

sum = 125

5 0

3 years ago

Emergencyyy

xxMikexx [17]