I need to know the answer

A circle has an area of 50 square meters. Which answer is closest to the measure of its diameter?

gregori [183]

Area of a circle is computed by multiplying pi to the square of the circle's radius.

A = πr²
50m² = 3.14 r²
50m²/3.14 = r²
r² = 15.92m²
r = √15.92m²
r = 3.99m

Diameter is computed by multiplying the radius twice.
d = 2r
d = 2(3.99m)
d = 7.98m or rounded up to 8 m

8 0

3 years ago

Expand the expression and combine like terms: 4(1.75y−3.5)+1.25y

Bas_tet [7]

4(1.75y−3.5)+1.25y . First multiply through with 4 the numbers in the parentheses. 7y➖ 14 ➕ 1.25y add 1.25y to 7y That will be 8.25y So the answer will be 8.25y ➖ 14

8 0

3 years ago

If The 3rd term of an A.S is and 5th term is . What is an A.P?

Bad White [126]

Question:

If The 3rd term of an A.S 23 is and 5th term is 15 .P What is an A.?

Answer:

A.P is 31, 27, 23 ,19, 15, 11, 7, 3

Step-by-step explanation:

Given:

3rd term = 23

5th term = 15

To Find:

The arithmetic Progression = ?

Solution:

Let

$a_1$ be the first term and d be difference

Then the arithmetic progression will be ,

$a_1 , (a_1+d),(a_1 +2d),......(a_1+(n-1)d)$

From the question ,

third term = 13

$(a_1 +2d) = 23$ -------------(1)

Similarly

$(a_1 +4d) = 15$ -----------------(2)

Subtracting (1) from (2) we get

-2d =8

$d = \frac{8}{2}$

d = -4

Substituting d = 4 in equation 1, we get

$(a_1 +2(-4)) = 23$

$(a_1 -8) = 23$

$a_1 = 23 +8$

$a_1 = 31$

$a_1 , (a_1+d),(a_1 +2d),......(a_1+(n-1)d)$

= 31 ,(31 +(-4)) ,(31 +2(-4)), (31+3(-4)).........

=> 31, 27, 23 , 19, 15, 11,7,3

3 0

4 years ago

ASK YOUR TEACHER An article reported that for a sample of 42 kitchens with gas cooking appliances monitored during a one-week pe

xxMikexx [17]

Answer:

$654.16-2.02\frac{165.23}{\sqrt{42}}=602.66$

$654.16+2.02\frac{165.23}{\sqrt{42}}=705.66$

So on this case the 95% confidence interval would be given by (602.66;705.66)

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

$\bar X=654.16$ represent the sample mean

$\mu$ population mean (variable of interest)

s=165.23 represent the sample standard deviation

n=42 represent the sample size

Solution to the problem

The confidence interval for the mean is given by the following formula:

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

In order to calculate the critical value $t_{\alpha/2}$ we need to find first the degrees of freedom, given by:

$df=n-1=42-1=41$

Since the Confidence is 0.95 or 95%, the value of $\alpha=0.05$ and $\alpha/2 =0.025$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.025,41)".And we see that $t_{\alpha/2}=2.02$

Now we have everything in order to replace into formula (1):

$654.16-2.02\frac{165.23}{\sqrt{42}}=602.66$

$654.16+2.02\frac{165.23}{\sqrt{42}}=705.66$

So on this case the 95% confidence interval would be given by (602.66;705.66)

7 0

4 years ago

At the Rockville middle school carnival, 4 of the first 160 people who played the ring toss game won the first prize, 8 won the

Klio2033 [76]

160-4-8-12 =136
136 out of 160 participants did not win a prize, so the experimental probability is
136/160=17/20

6 0

3 years ago