Please help me with question no.1 and 2. chapter ; circles

A set of data has the trend line modeled by the equation Y =1.5x + 11. What value of X corresponds to y =56?

erica [24]

Answer:

x = 30

Step-by-step explanation:

Plug in 56 in place of y, then solve for x.

56 = 1.5x + 11

Subtract 11.

45 = 1.5x

Divide both sides by 1.5.

45/1.5 = x

30 = x

8 0

3 years ago

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Write 7/20 as a percent.<br><br> By what factor should you multiply the denominator and numerator?

levacccp [35]

Answer:

35%

Step-by-step explanation:

Use photomath it tells you everything.

6 0

3 years ago

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free 69 points A rectangular prism has a length of 8 meters, a width of 6 meters, and a height of 3 meters. Which equations coul

anyanavicka [17]

Answer:

V = 8 × 6 × 3

V = 48*3

Step-by-step explanation:

V = l*w*h

We know the length is 8, the width is 6 and the height is 3

V = 8*6*3

V = 48*3

8 0

3 years ago

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Suppose a food scientist wants to determine whether two experimental preservatives result in different mean shelf lives for bana

melomori [17]

Answer:

The two sample t-test

Step-by-step explanation:

The appropriate test for thus is the two sample t test which is also known as the independent t test. This tests aims at determined whether there is a statistically significant difference between the means in two unrelated groups which in this context are a random sample with one type of preservative and another sample with another type of preservatives.

With this test, the researcher is able to compare the mean shelf lives of the bananas treated with the two different preservatives... The null hypothesis equalises the two means of the sample while the alternative does otherwise.

3 0

3 years ago

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

3 years ago

Please help me with question no.1 and 2. chapter ; circles​

Please help me with question no.1 and 2. chapter ; circles