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artcher [175]
3 years ago
11

Please help me I have 2 questions.

Mathematics
1 answer:
Maru [420]3 years ago
5 0
For the first one, with Bob and James, it takes Bob 1 roof for every 16 hours per roof ( 1/10)
James can finish 1 every 16 hours, ( 1/16)
1/10 + 1/16=1/t
8/80 + 5/80=1t
13/80=1t
now you would cross multiply
13(t)=1(80)
13t=80
t=6.15
It would take them 6.15 hours to finish!

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Need help with graph
andre [41]

Because the domain refers to the set of possible input values, the domain of a graph consists of all the input values shown on the x-axis. The range is the set of possible output values, which are shown on the y-axis.

The domain is the values of x between 1 and 7

The range

4 0
1 year ago
I need help with this <br> ASAP!!
liraira [26]

Answer:=

−243 /512 Fraction

4 0
3 years ago
Which of the following is a step in simplifying the expression x multiplied by y to the power of 3 over x to the power of negati
stich3 [128]

Answer:

-3

Step-by-step explanation:

5 0
3 years ago
given sin A =3/-/34 and that angle S is in quadrant 1, find the exact value of tan A in simplest radical form using a ration
Vedmedyk [2.9K]

Answer:

\tan(A) = \frac{3}{5}

Step-by-step explanation:

Given

\sin(A) = \frac{3}{\sqrt {34}}

0 \le A \le 90 --- First Quadrant

Required

Find tan(A)

The sin of an angle is:

\tan(A) = \frac{Opposite}{Hypotenuse}

and

\sin(A) = \frac{3}{\sqrt {34}}

By comparison:

Opposite = 3

Hypotenuse = \sqrt{34

So, the Adjacent is:

Hypotenuse^2 = Adjacent^2 + Opposite^2

(\sqrt{34})^2 = Adjacent^2 + 3^2

34 = Adjacent^2 + 9

Collect like terms

Adjacent^2 =34 - 9

Adjacent^2 =25

Take square roots

Adjacent =\sqrt{25

Adjacent =5

The tangent of an angle is:

\tan(A) = \frac{Opposite}{Adjacent}

This gives:

\tan(A) = \frac{3}{5}

8 0
3 years ago
Suppose a local manufacturing company claims their production line has a variance of less than 9.0. A quality control engineer d
Alexxx [7]

Answer:

\chi^2 =\frac{35-1}{9} 2.12^2 =16.979

p_v =P(\chi^2

If we compare the p value and the significance level provided we see that p_v so on this case we have enough evidence in order to reject the null hypothesis at the significance level provided. And that means that the population variance is significantly lower than 9

Step-by-step explanation:

Notation and previous concepts

A chi-square test is "used to test if the variance of a population is equal to a specified value. This test can be either a two-sided test or a one-sided test. The two-sided version tests against the alternative that the true variance is either less than or greater than the specified value"

n=35 represent the sample size

\alpha=0.01 represent the confidence level  

s =2.12 represent the sample deviation obtained

\sigma_0 =3 represent the value that we want to test

Null and alternative hypothesis

On this case we want to check if the population variance specification is lower than 9 and the deviation lower than 3, so the system of hypothesis would be:

Null Hypothesis: \sigma^2 \geq 9

Alternative hypothesis: \sigma^2

Calculate the statistic  

For this test we can use the following statistic:

\chi^2 =\frac{n-1}{\sigma^2_0} s^2

And this statistic is distributed chi square with n-1 degrees of freedom. We have eveything to replace.

\chi^2 =\frac{35-1}{9} 2.12^2 =16.979

Calculate the p value

In order to calculate the p value we need to have in count the degrees of freedom , on this case df= n-1= 35-1=34. And since is a left tailed test the p value would be given by:

p_v =P(\chi^2

In order to find the p value we can use the following code in excel:

"=CHISQ.DIST(16.979,34,TRUE)"

Conclusion

If we compare the p value and the significance level provided we see that p_v so on this case we have enough evidence in order to reject the null hypothesis at the significance level provided. And that means that the population variance is significantly lower than 9

6 0
3 years ago
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