Suppose that 15 inches of wire costs 45 cents. At the same rate, how many inches of wire can be bought for 24 cents? Please help

The answer is 72cm^2 because the area of a triangle is h x b divided by two because the triangle is half of a square, since the square is side times side, the answer is 12x12 divided by two, wich is 144/2. The final answer is 72

5 0

2 years ago

Read 2 more answers

4/5w-12=2/3w<br> what is the step by step answer to those equation?

Mariulka [41]

Kulay, there is no such thing as a "step by step answer" here. You seem to want a "step by step solution."

I must assume that by 4/5 you actually meant (4/5) and that by 2/3 you meant (2/3). Then your equation becomes:

(4/5)w - 12 = (2/3)w.

The LCD here is 5*3, or 15, so mult. every term by 15:

12w - 180 = 10w.
Add 180 to both sides, obtaining 12 w - 180 + 180 = 10w + 180.

Then 12w = 10w + 180. Simplifying, 2w = 180. What is w?

4 0

3 years ago

Polymer composite materials have gained popularity because they have high strength to weight ratios and are relatively easy and

Brums [2.3K]

Answer:

$t=\frac{51.6-48}{\frac{1.1}{\sqrt{10}}}=10.349$

$p_v =P(t_9>10.349)=1.34x10^{-6}$

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 reject the null hypothesis, and the the actual mean is significantly higher than 48 MPa at 5% of significance.

Step-by-step explanation:

1) Data given and notation

$\bar X=51.6$ represent the sample mean

$s=1.1$ represent the standard deviation for the sample

$n=10$ sample size

$\mu_o =48$ represent the value that we want to test

$\alpha=0.05$ 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 mean score is higher than 48, the system of hypothesis would be:

Null hypothesis: $\mu \geq 48$

Alternative hypothesis: $\mu > 48$

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:

$t=\frac{\bar X-\mu_o}{\frac{\sigma}{\sqrt{n}}}$ (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:

$t=\frac{51.6-48}{\frac{1.1}{\sqrt{10}}}=10.349$

Calculate the P-value

First we find the degrees of freedom:

$df=n-1=10-1=9$

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

$p_v =P(t_9>10.349)=1.34x10^{-6}$

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 reject the null hypothesis, and the the actual mean is significantly higher than 48 MPa at 5% of significance.

5 0

3 years ago