Write a number that is greater than 100 and less than 1000.

Help !!!!! It’s algebra :(

Naily [24]

Answer:

18 is the answer to your question.

8 0

3 years ago

Read 2 more answers

Janet worked 3 hours more than David and 7 hours less than Kate. David earned $7.50 per hour, Janet earned $6 per hour, and Kate

grandymaker [24]

We want to write and solve a system of equations to see how much each person earns.

What each one earned is:

Janet = $78
Kate = $180
David = $75

Let's define:

J = number of hours that Janet worked.
D = number of hours that David worked.
K = number of hours that Kate worked.

The information is:

<em>"Janet worked 3 hours more than David and 7 hours less than Kate"</em>

From this we can write:

J = D + 3

J = K - 7

We know that:

David earned $7.50 per hour.
Janet earned $6 per hour.
Kate earned $9 per hour.

Finally, we know that Kate earned $27 more than David an Janet combined, then we can write:

$9*K = $27 + ($7.50)*D + $6*J

Then we have a system of equations:

J = D + 3

J = K - 7

$9*K = $27 + ($7.50)*D + $6*J

We can rewrite the first and second equations to get:

D = J - 3

K = J + 7

Now we can replace these two in the other equation to get:

$9*(J + 7) = $27 + ($7.50)*(J - 3)+ $6*J

Now we can solve this for J:

$9*J + $63 = $27 + $7.50*J - $22.50 + $6*J

$9*J - $7.50*J - $6*J = $27 - $63 - $22.50

-$4.50*J = -$58.60

J = (-$58.60)/(-$4.50) = 13

This means that Janet worked for 13 hours.

And with:

K = J + 7 = 13 + 7 = 20

D = J - 3 = 13 - 3 = 10

We can see that Kate worked for 20 hours and David for 10 hours.

Then each one of them earned:

Janet = 13*$6 = $78

Kate = 20*$9 = $180

David = 10*$7.50 = $75

If you want to learn more, you can read:

brainly.com/question/9351049

5 0

2 years ago

What is the value of ¡97 - i?

Mrrafil [7]

Answer:

This is the answer

Step-by-step explanation:

3 0

3 years ago

Parker marks sixths on a number line. He writes

Paul [167]

Answer:

1 and 1/6

Step-by-step explanation:

the first mark after 1 would be a sixth of the way to the second whole number, 2

3 0

2 years ago

It is claimed that automobiles are driven on average more than 20,000 kilometers per year. To test this claim, 100 randomly sele

kow [346]

Answer:

$t=\frac{23500-20000}{\frac{3900}{\sqrt{100}}}=8.974$

$p_v =P(t_{99}>8.974)=9.43x10^{-15}$

If we compare the p value and the significance level given for example $\alpha=0.05$ we see that $p_v$ so we can conclude that we to reject the null hypothesis, and the actual mean is significantly higher than 20000.

Step-by-step explanation:

1) Data given and notation

$\bar X=23500$ represent the sample mean

$s=3900$ represent the sample standard deviation

$n=100$ sample size

$\mu_o =2000$ represent the value that we want to test

$\alpha$ represent the significance level for the hypothesis test.

t would represent the statistic (variable of interest)

$p_v$ represent the p value for the test (variable of interest)

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to determine if the true mean is higher than 20000, the system of hypothesis would be:

Null hypothesis: $\mu \leq 2000$

Alternative hypothesis: $\mu > 2000$

We don't know the population deviation, so for this case is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:

$t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}$ (1)

t-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

Calculate the statistic

We can replace in formula (1) the info given like this:

$t=\frac{23500-20000}{\frac{3900}{\sqrt{100}}}=8.974$

Calculate the P-value

First we need to calculate the degrees of freedom given by:

$df=n-1=100-1=99$

Since is a one-side upper test the p value would be:

$p_v =P(t_{99}>8.974)=9.43x10^{-15}$

Conclusion

If we compare the p value and the significance level given for example $\alpha=0.05$ we see that $p_v$ so we can conclude that we to reject the null hypothesis, and the actual mean is significantly higher than 20000.

8 0

2 years ago