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3 years ago

7

please work it out and don't waste points man do it only if you know how to work it out because everyone's been wasting my point

s :(

1 answer:

olga2289 [7]3 years ago

4 0

Answer:

Please refer to the attachment

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uppose that an automobile manufacturer advertises that its new hybrid car has a mean gas mileage of 50 miles per gallon. You tak

Harlamova29_29 [7]

Answer:

$t=\frac{47-50}{\frac{5.5}{\sqrt{30}}}=-2.988$

$p_v =2*P(t_{(29)}$

If we compare the p value and the significance level given $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to fail reject the null hypothesis, so we can conclude that the true mean is significantly different from 50 mpg at 5% of signficance.

Step-by-step explanation:

Data given and notation

$\bar X=47$ represent the sample mean

$s=5.5$ represent the sample standard deviation

$n=30$ sample size

$\mu_o =50$ represent the value that we want to test

$\alpha=0.01$ 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 check if the true mean is 50 or no, the system of hypothesis would be:

Null hypothesis: $\mu = 50$

Alternative hypothesis: $\mu \neq 50$

If we analyze the size for the sample is = 30 but we don't know the population deviation so 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:

$t=\frac{47-50}{\frac{5.5}{\sqrt{30}}}=-2.988$

P-value

The first step is calculate the degrees of freedom, on this case:

$df=n-1=30-1=29$

Since is a two tailed test the p value would be:

$p_v =2*P(t_{(29)}$

Conclusion

If we compare the p value and the significance level given $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to fail reject the null hypothesis, so we can conclude that the true mean is significantly different from 50 mpg at 5% of signficance.

4 0

3 years ago

Steve works two different jobs for a total of 60 hours every Monday through Friday schedule is the same each day and he works th

Semenov [28]

Answer:

Step-by-step explanation:

Steve works:

- 60 hour per week = 12 hours per day (60/5)

- first job: 3 hours per day = 15 hours per week

- x = second job hours per day

equitation:

1st option to calculate:

12 (total hours per day) = 3 (hours per day on first job) + X

9 = X

2nd option to calculate:

60(total hours per week) = 15 (3 hours per day x 5) + x

45 = x

you need to divide 45 / 5 to get the daily hours which is 9

4 0

3 years ago

What happens to the sign or signs of the coordinates when you reflect a point?

elena55 [62]

Part a: Reflecting a point across the x-axis, changes the sign of the y-coordinate.

Part b: Reflecting a point across the y-axis, changes the sign of the x-coordinate.

Part c: Reflecting a point across both the axes, changes the signs of both the coordinates.

Explanation:

Part a: Reflecting a point across the x-axis

The reflection is a transformation of a figure which represents a flip.

The rule for a reflection over the x -axis is given by

$(x, y) \rightarrow(x,-y)$

Hence, this represents the change of sign of the y-coordinate.

Thus, Reflecting a point across the x-axis, changes the sign of the y-coordinate.

Part b: Reflecting a point across the y-axis

The rule for a reflection over the y -axis is given by

$(x, y) \rightarrow(-x, y)$

Hence, this represents the change of sign of the x-coordinate.

Thus, Reflecting a point across the y-axis, changes the sign of the x-coordinate.

Part c: Reflecting a point across both the axes

The rule for a reflection across both the axes is given by

$(x, y) \rightarrow(-x, -y)$

Hence, this represents the changes the signs of both the coordinates.

Thus, Reflecting a point across both the axes, changes the signs of both the coordinates.

6 0

3 years ago

At the ice cream parlor there are thirty flavors, but for the last week they have only had 25 flavors.

myrzilka [38]

Answer: Percent change = 20%

===========================================================

Work Shown:

A = old value = 25 (last week's number)

B = new value = 30 (current week's number)

C = percent change

C = [ (B-A)/A ] * 100%

C = [ (30-25)/25 ] * 100%

C = [ 5/25 ] * 100%

C = 0.20* 100%

C = 20%

The percent change is 20%

The positive value of C indicates we have a percent increase.

8 0

3 years ago

A right triangle has legs measuring 4.5 meters and 1.5 meters. The lengths of the legs of a second triangle are proportional to

Eduardwww [97]

Any multiples of 4.5:1.5 would work because being proportional just depends on whether you can reduce to get the same answer of the first triangle. You could do anything like 9m and 3m or 27m and 9m

4 0

3 years ago