PLEASE HELP ME I NEED SO MUCH HELP <br> I'LL GIVE YOU BRANIEST

Help or don’t if so thank you

NikAS [45]

Answer: 12.60 per CD

Step-by-step explanation:

Tax 0.80 * 3 = 2.40

40.20 - 2.40 = 37.80

37.8 / 3 = 12.60

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

If triangle ABC is similar to triangle DEC, find the values of x and y.

Mumz [18]

The values are x=8 and y=35, if the given ΔABC and ΔDEC are equal, it is obtained by Pythagoras theorem.

Step-by-step explanation:

The given are,

From ΔABC,

AB= 6

BC= 10

AC = x

From ΔDEC,

CD= 28

DE= 21

CE = y

Step:1

Pythagoras theorem from ΔABC,

$BC^{2}=AB^{2} + AC^{2}$ ...............(1)

Substitute the values,

$10^{2}$ = $6^{2}$ + $AC^{2}$

100 = 36 + $AC^{2}$

$AC^{2}$ = 100 - 36

= 64

AC = $\sqrt{64}$

AC = 8

AC = x = 8

Step:2

Pythagoras theorem for ΔDEC,

$CE^{2} = CD^{2} + DE^{2}$ ................(2)

From the values,

$CE^{2}$ = $28^{2}$ + $21^{2}$

$CE^{2}$ = 784 + 441

= 1225

CE = $\sqrt{1225}$

CE = 35

CE = y = 35

Result:

The values are x=8 and y=35, if the given ΔABC and ΔDEC are equal.

5 0

3 years ago

If my phone bill is calculated using equation c= 50g +75 what is the value and interpretation of the slope of this equation? C=

olga nikolaevna [1]

Answer:

The value of the slope in this equation is 50

The interpretation is that the rate of change in the cost of the phone bill per unit change in gigabytes of data used each month is 50

Step-by-step explanation:

To answer this question, we need to compare the given equation with the equation of a straight line graph.

The equation we have is;

c = 50g + 75

comparing this with the equation of a straight line, we have

y = mx + c

where m represents the slope and c is the y-intercept

So comparing both, the slope of the equation is 50.

The slope is always the co-efficient of the value on the x-axis

So what does this mean?

The slope also called the gradient represents the rate of change of the y-term divided by the rate of change of the x-term. In simpler terms, when we talk of the slope, we mean the rate of change of the y term per the unit change of the x-term.

So what we mean in this case is the rate of change in cost of the phone bill per unit change in gigabytes of data used each month is 50

3 0

3 years ago

What is the problem a+9.5=14.1

Romashka-Z-Leto [24]

Answer: a=4.6

Step-by-step explanation:

8 0

3 years ago

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PLEASE HELP ME I NEED SO MUCH HELP I'LL GIVE YOU BRANIEST