What is the length of side BC? PLEASE HELP!

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

The pythagorean theorem equation

nikklg [1K]

A^2+b^2=c^2
Is the Pythagorean theorem

6 0

3 years ago

Read 2 more answers

Las+salchichas+vienen+en+paquetes+de+6+y+los+panes+para+panchos+se+envasan+en+paquetes+de+8+unidades+¿Es+cierto+que+si+se+prepar

vovikov84 [41]

Answer:

Es cierto se usan 16 paquetes de salchichas y 12 paquetes de panes para pancho.

Step-by-step explanation:

Lo que debemos hacer en este caso es dividir la cantidad total de panchos primero por la cantidad de unidades de salchichas que vienen en su paquete y segundo por la cantidad de unidades de panes para panchos que vienen en su paquete, si el resultado nos da un numero entero podemos decir que usa una cantidad completa de paquetes de salchichas y de panes:

96/6 = 16

96/8 = 12

Es decir que para 96 panchos se usan 16 paquetes de salchichas y 12 paquetes de panes para pancho, por lo tanto es cierto.

8 0

3 years ago

(1+v)(v-7) i need help to solve this question

kramer

(1 + v)(v - 7)

1*(v - 7) + v(v - 7)

1*v - 1*7 + v*v - v*7

v - 7 + v² - 7v

v² - 7v + v - 7

v² - 6v - 7

I hope this helps.

4 0

3 years ago

How do I solve this equation?

inn [45]

You can use substitution or elimination or graphing to solve the equation. Since both of the equations are in slope intercept form it will be easier to use substitution or to graph it and find the point of interception.

5 0

3 years ago

Read 2 more answers