Please help a. 6 b. 4 c. 8 d. 2

The cost of a gallon of gas increased from $3.54 to $3.87 over the weekend. What is the percent increase for the cost of gas, ro

Dmitrij [34]

Answer:

9%

Step-by-step explanation:

percent increase is calculated as

$\frac{increase}{original}$ × 100%

increase = $3.87 - $3.54 = $0.33 , then

% increase = $\frac{0.33}{3.54}$ × 100% ≈ 9% ( to the nearest whole percent )

5 0

1 year ago

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Quick I need help!

kkurt [141]

Im not too sure but i would say 27

5 0

3 years ago

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How do I multiply fractions by whole numbers

Volgvan

Multiplying fractions by whole numbers:
1. You have to convert the whole number into an improper fraction.
2. You then multiply the fractions straight across.
Ex: 2/3 × 6 =2/3 × 6/1 = 2×6/3×1= 12/3= 4

5 0

3 years ago

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An auto company claims that the fuel efficiency of its sedan has been substantially improved. A consumer advocate organization w

zzz [600]

Answer:

$t=\frac{\bar d -0}{\frac{s_d}{\sqrt{n}}}=\frac{0.983 -0}{\frac{1.685}{\sqrt{12}}}=2.021$

$df=n-1=12-1=11$

$p_v =P(t_{(11)}>2.021) =0.0342$

If we compare the the p value with the significance level provided $\alpha=0.1$ , we see that $p_v < \alpha$ , so then we can reject the null hypothesis. and there is a significant increase in the miles per gallon from 2017 to 2019 at 10% of significance.

Step-by-step explanation:

Previous concepts

A paired t-test is used to compare two population means where you have two samples in which observations in one sample can be paired with observations in the other sample. For example if we have Before-and-after observations (This problem) we can use it.

Let put some notation :

x=test value 2017 , y = test value 2019

x: 28.7 32.1 29.6 30.5 31.9 30.9 32.3 33.1 29.6 30.8 31.1 31.6

y: 31.1 32.4 31.3 33.5 31.7 32.0 31.8 29.9 31.0 32.8 32.7 33.8

Solution to the problem

The system of hypothesis for this case are:

Null hypothesis: $\mu_y- \mu_x \leq 0$

Alternative hypothesis: $\mu_y -\mu_x >0$

Because if we have an improvement we expect that the values for 2019 would be higher compared with the values for 2017

The first step is calculate the difference $d_i=y_i-x_i$ and we obtain this:

d: 2.4, 0.3, 1.7,3,-0.2, 1.1, -0.5, -3.2, 1.4, 2, 1.6, 2.2

The second step is calculate the mean difference

$\bar d= \frac{\sum_{i=1}^n d_i}{n}= \frac{11.8}{12}=0.983$

The third step would be calculate the standard deviation for the differences, and we got:

$s_d =\frac{\sum_{i=1}^n (d_i -\bar d)^2}{n-1} =1.685$

We assume that the true difference follows a normal distribution. The 4th step is calculate the statistic given by :

$t=\frac{\bar d -0}{\frac{s_d}{\sqrt{n}}}=\frac{0.983 -0}{\frac{1.685}{\sqrt{12}}}=2.021$

The next step is calculate the degrees of freedom given by:

$df=n-1=12-1=11$

Now we can calculate the p value, since we have a right tailed test the p value is given by:

$p_v =P(t_{(11)}>2.021) =0.0342$

If we compare the the p value with the significance level provided $\alpha=0.1$ , we see that $p_v < \alpha$ , so then we can reject the null hypothesis. and there is a significant increase in the miles per gallon from 2017 to 2019 at 10% of significance.

4 0

2 years ago

Plz answer.............

spayn [35]

Answer:

( - x, - y )

Step-by-step explanation:

The starting is always Quadrant I.

270 degrees clockwise from Quadrant I is Quadrant III.

In Quadrant III, the points will be in the form ( - x, - y ).

7 0

2 years ago