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3 years ago

15

Use the graphing calculator to graph the quadratic function y = 2x2 – 6x – 8. Which values are solutions of 0 = 2x2 – 6x – 8? Ch

eck all that apply. –4 ,–1 ,0 ,1 ,4

2 answers:

SashulF [63]3 years ago

7 0

4 is your answer. hope its correct

umka2103 [35]3 years ago

5 0

Answer:

-1, and 4

Step-by-step explanation:

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ann arranges her marbles in groups, with 8 marbles in each group. She writes the fraction 5/8 to show the fraction of marbles in

DerKrebs [107]

If there are 8 marbles in a group , and 5 out of every 8 is red, than in six groups there would be 5, 10, 15, 20, 25, 30 red marbles.

This lists the group of 6 sets.

30 red marbles in 6 sets.

8 0

4 years ago

Two major automobile manufacturers have produced compact cars with engines of the same size. We are interested in determining wh

Molodets [167]

Answer:

(A) The mean for the differences is 2.0.

(B) The test statistic is 1.617.

(C) At 90% confidence the null hypothesis should not be rejected.

Step-by-step explanation:

We are given that a random sample of eight cars from each manufacturer is selected, and eight drivers are selected to drive each automobile for a specified distance.

The following data (in miles per gallon) show the results of the test;

Driver Manufacturer A Manufacturer B

1 32 28

2 27 22

3 26 27

4 26 24

5 25 24

6 29 25

7 31 28

8 25 27

Let $\mu_1$ = mean MPG for the fuel efficiency of Manufacturer A brand

$\mu_2$ = mean MPG for the fuel efficiency of Manufacturer B brand

SO, Null Hypothesis, $H_0$ : $\mu_1-\mu_2=0$ or $\mu_1= \mu_2$ {means that there is a not any significant difference in the mean MPG (miles per gallon) when testing for the fuel efficiency of these two brands of automobiles}

Alternate Hypothesis, $H_A$ : $\mu_1-\mu_2\neq 0$ or $\mu_1\neq \mu_2$ {means that there is a significant difference in the mean MPG (miles per gallon) for the fuel efficiency of these two brands of automobiles}

The test statistics that will be used here is <u>Two-sample t test statistics</u> as we don't know about the population standard deviations;

T.S. = $\frac{(\bar X_1-\bar X_2)-(\mu_1-\mu_2)}{s_p\sqrt{\frac{1}{n_1}+\frac{1}{n_2} } }$ ~ $t__n__1+_n__2-2$

where, $\bar X_1$ = sample mean MPG for manufacturer A = $\frac{\sum X_A}{n_A}$ = 27.625

$\bar X_2$ = sample mean MPG for manufacturer B = $\frac{\sum X_B}{n_B}$ = 25.625

$s_1$ = sample standard deviation for manufacturer A = $\sqrt{\frac{\sum (X_A-\bar X_A)^{2} }{n_A-1} }$ = 2.72

$s_2$ = sample standard deviation manufacturer B = $\sqrt{\frac{\sum (X_B-\bar X_B)^{2} }{n_B-1} }$ = 2.20

$n_1$ = sample of cars selected from manufacturer A = 8

$n_2$ = sample of cars selected from manufacturer B = 8

Also, $s_p=\sqrt{\frac{(n_1-1)s_1^{2}+(n_2-1)s_2^{2} }{n_1+n_2-2} }$ = $\sqrt{\frac{(8-1)\times 2.72^{2}+(8-1)\times 2.20^{2} }{8+8-2} }$ = 2.474

(A) The mean for the differences is = 27.625 - 25.625 = 2

(B) <u><em>The test statistics</em></u> = $\frac{(27.625-25.625)-(0)}{2.474 \times \sqrt{\frac{1}{8}+\frac{1}{8} } }$ ~ $t_1_4$

= 1.617

(C) Now at 10% significance level, the t table gives critical values between -1.761 and 1.761 at 14 degree of freedom for two-tailed test. Since our test statistics lies within the range of critical values of t, so we have insufficient evidence to reject our null hypothesis as it will not fall in the rejection region due to which <u>we fail to reject our null hypothesis</u>.

Therefore, we conclude that there is a not any significant difference in the mean MPG (miles per gallon) when testing for the fuel efficiency of these two brands of automobiles.

5 0

4 years ago

Cual es la suma de los ángulos externos de un triángulo

mr_godi [17]

“what is the sum of the angles of a triangle” 180 degrees

4 0

3 years ago

to determine a student's grade, a teacher throws out the lowest grade obtained on 5 tests, averages the remaining grades, and ro

RoseWind [281]

Answer:

B grade

Step-by-step explanation:

75 + 90 + 88 + 86 = 339

339/4 = 84.75

Grade B = 80-89%

3 0

3 years ago

Read 2 more answers

What are the solutions to the system of equations? y=−x^2−5x−6 x+y=−3

Dmitriy789 [7]

Answer:

The solutions are the points (-3,0) and (-1,-2)

Step-by-step explanation:

we have

$y=-x^{2} -5x-6$ -----> equation A

$x+y=-3$ -----> equation B

Solve the system of equations by graphing

The solution of the system of equations are the intersection points both graphs

The solutions are the points (-3,0) and (-1,-2)

see the attached figure

5 0

3 years ago