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3 years ago

Work out the circumference of this circle.

Mathematics

1 answer:

nevsk [136]3 years ago

6 0

Answer:

About 28.3

Step-by-step explanation:

Formula=2 $\pi$ r

r=radius

d=diameter

radius is 1/2 of diameter

The diameter is 9 so the radius is 4.5

You might be interested in

The sum of two consecutive integers is one less than three times the smaller integer. Find the two integers.

Minchanka [31]

The small number is 2.

The large number is 3.

Step-by-step explanation:

Let the two consecutive numbers be x and x+1.

x be the small integer.
x+1 be the large integer.

The sum of these two consecutive integers = small integer + large integer

The sum of these two consecutive integers is x+x+1 = (2x+1)

It is given that,

The sum of two consecutive integers is one less than three times the smaller integer.
This means that, (2x+1) is one less than three times the smaller integer.
Here, the small integer is represented as x.

Therefore, it can determined that :

(2x+1) = 3x-1

Keeping x term on one side and constants on other side,

3x-2x = 1+1

x = 2

Therefore, the small number is 2 and the large number is x+1 = 3.

3 0

3 years ago

Solve. Simplify any irrational solutions. 2x^2-10x+11=0

liraira [26]

Solve for x
Isolate the variable by dividing each side by factors that don't contain the variable.
Exact Form:
x
=
19
10
x
=
19
10
Decimal Form:
x
=
1.9
x
=
1.9
Mixed Number Form:
x
=
1
9
10

4 0

3 years ago

Question text A savings and loan association needs information concerning the checking account balances of its local customers.

Aliun [14]

Answer:

The lower value for a 98% confidence interval for the true mean checking account balance for local customers is of $451.2.

Step-by-step explanation:

We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 14 - 1 = 13

98% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 13 degrees of freedom(y-axis) and a confidence level of $1 - \frac{1 - 0.98}{2} = 0.99$ . So we have T = 2.65

The margin of error is:

$M = T\frac{s}{\sqrt{n}} = 2.65\frac{297.29}{\sqrt{14}} = 212.94$

In which s is the standard deviation of the sample and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 664.14 - 212.94 = $451.2.

The lower value for a 98% confidence interval for the true mean checking account balance for local customers is of $451.2.

7 0

3 years ago

How would you factor out 8w-6w^3?? I have a math test tomorrow and went completely blank. :(

Sav [38]

The GCF here would be 2w, so divide each one by that. Now just divide by that, and multiply the quantity (amount in the parenthesis) by 2w so we don't have a different equation than the original. Now you have your answer: 2w(4w-3w^2)

8 0

3 years ago

Based on information from Harper’s Index, 37% of adult Americans believe in Extraterrestrials. Out of a random sample of 100 adu

san4es73 [151]

Answer:

z(s) is in the rejection zone , therefore we reject H₀

We have enough evidence to claim the proportion of individuals who attended college and believe in extraterrestrials is bigger than 37%

Step-by-step explanation:

We have a prortion test.

P₀ = 37 % P₀ = 0,37

sample size = n = 100

P sample proportion = P = 47 % P = 0,47

confidence interval 95 %

α = 0,05

One tail-test (right tail) our case is to show if sample give enough information to determine if proportion of individual who attended college is higher than the proportion found by Harper´s index.

1.-Hypothesis:

H₀ null hypothesis P₀ = 0,37

Hₐ alternative hypothesis P₀ > 0,37

2.-Confidence interval 95 %

α = 0,05 and z(c) = 1.64

3.-Compute of z(s)

z(s) = [ P - P₀ ] /√(P₀Q₀/n) ]

z(s) = [ ( 0,47 - 0,37 ) / √0.37*0,63/100

z(s) = 0,1 /√0,2331/100 ⇒ z(s) = 0,1 /0,048

z(s) = 2.08

4.-Compare z(s) and z(c)

z(s) > z(c) 2.08 > 1.64

5.-Decision:

z(s) is in the rejection zone , therefore we reject H₀

We have enough evidence to claim the proportion of individuals who attended college and believe in extraterrestrials is bigger than 37%

5 0

4 years ago