All categories

2 years ago

I have no idea how to answer this. please help me

Mathematics

1 answer:

Anastasy [175]2 years ago

4 0

Answer:

The perimeter is 36.

Step-by-step explanation:

You can see that the sides labeled are the same length as another side. And to get the perimeter you have to do 8+10+8+10=36

You might be interested in

A movie rental company charges a yearly membership fee of $18.Each movie rental is $1.50.Which equation could be used to find th

Pavlova-9 [17]

Answer:

18+1.50m

Step-by-step explanation:

7 0

3 years ago

I need help trying to find the answer to -4(x-1)=-3x+31

never [62]

-4x +4 = -3x + 31
4 - 31 = -3x + 4x
-27 = x

5 0

3 years ago

At Western University the historical mean of scholarship examination scores for freshman applications is 900. A historical popul

vampirchik [111]

Answer:

a) Null Hypothesis: $\mu =900$

Alternative hypothesis: $\mu \neq 900$

b) The 95% confidence interval would be given by (910.05;959.95)

c) Since we confidence interval not ocntains the value of 900 we fail to reject the null hypothesis that the true mean is 900.

d) $z=\frac{935 -900}{\frac{180}{\sqrt{200}}}=2.750$

Since is a bilateral test the p value is given by:

$p_v =2*P(Z>2.750)=0.0059$

Step-by-step explanation:

a. State the hypotheses.

On this case we want to check the following system of hypothesis:

Null Hypothesis: $\mu =900$

Alternative hypothesis: $\mu \neq 900$

b. What is the 95% confidence interval estimate of the population mean examination score if a sample of 200 applications provided a sample mean x¯¯¯= 935?

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

$\bar X=935$ represent the sample mean for the sample

$\mu$ population mean (variable of interest)

$\sigma=180$ represent the population standard deviation

n=200 represent the sample size

The confidence interval for the mean is given by the following formula:

$\bar X \pm z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (1)

In order to calculate the mean and the sample deviation we can use the following formulas:

$\bar X= \sum_{i=1}^n \frac{x_i}{n}$ (2)

$s=\sqrt{\frac{\sum_{i=1}^n (x_i-\bar X)}{n-1}}$ (3)

The mean calculated for this case is $\bar X=3278.222$

The sample deviation calculated $s=97.054$

Since the Confidence is 0.95 or 95%, the value of $\alpha=0.05$ and $\alpha/2 =0.025$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-NORM.INV(0.025,0,1)".And we see that $z_{\alpha/2}=1.96$

Now we have everything in order to replace into formula (1):

$935-1.96\frac{180}{\sqrt{200}}=910.05$

$935+1.96\frac{180}{\sqrt{200}}=959.95$

So on this case the 95% confidence interval would be given by (910.05;959.95)

c. Use the confidence interval to conduct a hypothesis test. Using α= .05, what is your conclusion?

Since we confidence interval not ocntains the value of 900 we fail to reject the null hypothesis that the true mean is 900.

d. What is the p-value?

The statistic is given by:

$z=\frac{\bar X -\mu}{\frac{\sigma}{\sqrt{n}}}$

If we replace we got:

$z=\frac{935 -900}{\frac{180}{\sqrt{200}}}=2.750$

Since is a bilateral test the p value is given by:

$p_v =2*P(Z>2.750)=0.0059$

So then since the p value is less than the significance we can reject the null hypothesis at 5% of significance.

8 0

3 years ago

A study of class attendance and grades among first-year students at a state university showed that, in general, students who mis

ratelena [41]

Answer:

the numerical value of the correlation between percent of classes attended and grade index is r = 0.4

Step-by-step explanation:

Given the data in the question;

we know that;

the coefficient of determination is r²

while the correlation coefficient is defined as r = √(r²)

The coefficient of determination tells us the percentage of the variation in y by the corresponding variation in x.

Now, given that class attendance explained 16% of the variation in grade index among the students.

coefficient of determination is r² = 16%

The correlation coefficient between percent of classes attended and grade index will be;

r = √(r²)

r = √( 16% )

r = √( 0.16 )

r = 0.4

Therefore, the numerical value of the correlation between percent of classes attended and grade index is r = 0.4

3 0

3 years ago

What is the range of (fog)(x)?

scoray [572]

Answer:

y=x

Step-by-step explanation:

domain: all real numbers

range: all real numbers

X/Y Intercept: (0,0)

7 0

3 years ago