Find the value of a squared + b when a= -2 and b=5

Mathematics

1 answer:

ollegr [7]3 years ago

6 0

Answer:

Step-by-step explanation:

a²+b where a= -2, b=5

(-2)²+(5)

=4+5

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You are trying to estimate the average amount a family spends on food during a year. In the past the standard deviation of the a

svetoff [14.1K]

Answer:

$n=(\frac{2.58(1000)}{50})^2 =2662.56 \approx 2663$

So the answer for this case would be n=2663 rounded up to the nearest integer

Step-by-step explanation:

We have the following info:

$ME = 50$ margin of error desired

$\sigma = 1000$ the standard deviation for this case

The margin of error is given by this formula:

$ME=z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (a)

And on this case we have that ME =50 and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=(\frac{z_{\alpha/2} \sigma}{ME})^2$ (b)

The critical value for 99% of confidence interval now can be founded using the normal distribution. The significance is $\alpha=0.01$ . And for this case would be $z_{\alpha/2}=2.58$ , replacing into formula (b) we got:

$n=(\frac{2.58(1000)}{50})^2 =2662.56 \approx 2663$

So the answer for this case would be n=2663 rounded up to the nearest integer

5 0

3 years ago

What is the value of x and the length of segment DE?

aniked [119]

Answer:

x = 6.6; DE = 16.6

Step-by-step explanation:

Assume the diagram is like the figure below.

1. Calculate the value of x

In a right triangle, the altitude drawn from the right angle to the hypotenuse divides the triangle into two similar triangles.

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