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3 years ago

The radius of a circle is (2x-3). What is a function for the area of the circle?

Mathematics

1 answer:

Oduvanchick [21]3 years ago

6 0

Answer

A = pi * r^2

= pi * (2x^-3)^2

= pi * 2^2 * (x^-3)^2

= pi * 4 * (x^-6)

= 4*pi * x^-6

Step-by-step explanation:

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Which statement is true?

Maslowich

Answer:

Step-by-step explanation:

on the left of the equation, (6^4)^-5 = 6^-20

the right side you add the exponents so it would be (-7-3) =-10

so it would be 6^-10, which is greater than 6^-20

5 0

2 years ago

83 random samples were selected from a normally distributed population and were found to have a mean of 32.1 and a standard devi

arlik [135]

Answer:

$\frac{(82)(2.4)^2}{104.139} \leq \sigma^2 \leq \frac{(82)(2.4)^2}{62.132}$

$4.525 \leq \sigma^2 \leq 7.602$

Now we just take square root on both sides of the interval and we got:

$2.127 \leq \sigma \leq 2.757$

Step-by-step explanation:

Information given

$\bar X=32.1$ represent the sample mean

$\mu$ population mean (variable of interest)

s=2.4 represent the sample standard deviation

n=83 represent the sample size

Confidence interval

The confidence interval for the population variance is given by the following formula:

$\frac{(n-1)s^2}{\chi^2_{\alpha/2}} \leq \sigma^2 \leq \frac{(n-1)s^2}{\chi^2_{1-\alpha/2}}$

The degrees of freedom given by:

$df=n-1=8-1=7$

The confidence level is 0.90 or 90%, the value of $\alpha=0.1$ and $\alpha/2 =0.05$ , and we can use excel, a calculator or a table to find the critical values.

The excel commands would be: "=CHISQ.INV(0.05,82)" "=CHISQ.INV(0.95,82)". so for this case the critical values are:

$\chi^2_{\alpha/2}=104.139$

$\chi^2_{1- \alpha/2}=62.132$

The confidence interval is given by:

$\frac{(82)(2.4)^2}{104.139} \leq \sigma^2 \leq \frac{(82)(2.4)^2}{62.132}$

$4.525 \leq \sigma^2 \leq 7.602$

Now we just take square root on both sides of the interval and we got:

$2.127 \leq \sigma \leq 2.757$

5 0

3 years ago

If you are making broccoli cheese soup the ratio of cheese to broccoli to broth is 5:6:10 if there is 100 parts broth how many o

il63 [147K]

Answer: See explanation

Step-by-step explanation:

Since there are 100 parts broth, the number to use for each ingredients will be:

Cheese = 5 × 100/10 = 5 × 10 = 50

Broccoli = 6 × 100/10 = 6 × 10 = 60

Broth = 100

8 0

3 years ago

Which set only contains numbers that make the inequality true?

pashok25 [27]

Answer:

Step-by-step explanation:

3 + 19 = 22

4 + 19 = 23

5 + 19 = 24

6 + 19 = 25

All sums are less than 28

5 0

3 years ago

Read 2 more answers

If the triangle ABC~ triangle PQR, find value of y.

ale4655 [162]

C must be 80° to make the triangle angles add to 180°. The corresponding angles of similar triangles are congruent. So

Answer: y=80°

4 0

3 years ago