All categories

2 years ago

Pls can you solve this question from hegartymaths?

Mathematics

1 answer:

Sergeeva-Olga [200]2 years ago

8 0

The area of a circle with radius r is πr². So you need to find r such that

πr² = 56π

⇒ r² = 56

⇒ r = √56 = 2√14

You might be interested in

Ise9urgyobrhrstbydfdsfwefwefsdfewfds

ELEN [110]

Yeah I think x=12y on this one correct me if I’m wrong

3 0

2 years ago

I’ll give brainliest please help asap :D

USPshnik [31]

<h3>Answer:</h3><h3> C</h3><h3 /><h3>Step-by-step explanation:</h3><h3>It is C.</h3>

Thanks!

Hope i helped

4 0

2 years ago

Which could be the first step in solving this system of equations by substitution?

Ainat [17]

Answer:

The first step is to replace the y in y-x=15 with 7x (we can do this because the first equation tells us that they're equal)

solve and get

(2.5,17.5)

or x= 2.5 y=17.5

Step-by-step explanation:

The first step is to recognize that y=7x which means that we can just replace the y in the second equation with 7x

7x-x=15

6x=15

x=2.5

Then we can solve for y

y=7(2.5)

y=17.5

3 0

2 years ago

The value of homes sold in Hampton VA are normally distributed with a mean of $200,000 and a standard deviation of $10,000. If 1

LenKa [72]

Answer:

84%

Step-by-step explanation:

What we must do is calculate the z value for each value and thus find what percentage each represents and the subtraction would be the percentage between those two values.

We have that z is equal to:

z = (x - m) / (sd)

x is the value to evaluate, m the mean, sd the standard deviation

So for 190000 we have:

z = (190000 - 200000) / (10000)

z = -1

and this value represents 0.1587

for 230000 we have:

z = (230000 - 200000) / (10000)

z = 3

and this value represents 0.9987

we subtract:

0.9987 - 0.1587 = 0.84

Which means that it represents 84% of the houses

3 0

2 years ago

A survey of 80 randomly selected companies asked them to report the annual income of their presidents. Assuming that incomes are

Artyom0805 [142]

Answer:

The 90% confidence interval estimate of the mean annual income of all company presidents is ($579,545, $590,580).

Step-by-step explanation:

The information provided is:

$n=80\\\sigma=30,000\\\bar x=585062.50\\\text{Confidence level} = 90\%$

The critical value of <em>z</em> for 90% confidence level is, 1.645.

Compute the 90% confidence interval estimate of the mean annual income of all company presidents as follows:

$CI=\bar x\pm z_{\alpha/2}\cdot\frac{\sigma}{\sqrt{n}}\\\\=585062.50\pm 1.645\times\frac{30000}{\sqrt{80}}\\\\=585062.50\pm5517.50\\\\=(579545, 590580)$

Thus, the 90% confidence interval estimate of the mean annual income of all company presidents is ($579,545, $590,580).

This interval implies that there is 90% probability that the true mean annual income of all company presidents is within this interval.

4 0

2 years ago