50 POINTS STUCK

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

Explain how to find the estimated sum of 5/8+2/9 . Make sure to include at least one type of model.

OverLord2011 [107]

In this expression you would have to use the PEMDAS method. First divide, so (5 divided by 8) + (2 divided by 9).
The answer you would get is: (0.625) + (0.222)
The final answer is: 0.847

8 0

3 years ago

What is the least common denominator of<br> 1/3 and 5/9

crimeas [40]

Answer:

Equivalent Fractions with the LCD

1/3 = 3/9

5/9 = 5/9

Solution:

Rewriting input as fractions if necessary:

1/3, 5/9

For the denominators (3, 9) the least common multiple (LCM) is 9.

LCM(3, 9)

Therefore, the least common denominator (LCD) is 9.

Calculations to rewrite the original inputs as equivalent fractions with the LCD:

1/3 = 1/3 × 3/3 = 3/9

5/9 = 5/9 × 1/1 = 5/9

4 0

3 years ago

A hyena runs 2 kilometers for every 25 kilometer a mouse runs. Select from the drop-down menu to correctly complete the statemen

NARA [144]

Answer:

make a chart to see the difference between the two animals

5 0

2 years ago

Read 2 more answers

What is the area of a circle with radius of 3 inches? Use pie =3.14 A .18.84 square roots B .28.26 square roots C .9.42 square r

tatiyna

Answer:

B. 28.26

Step-by-step explanation:

First you have to find the circumference:

R²= 3²=9

Then you multiply your circumference by 3.14 to get you answer:

9·3.14=28.26

3 0

3 years ago