Solve the quadratic by factoring.<br> x^2+17=-10x-7x 2 +17=−10x−7

Two researchers conducted a study in which two groups of students were asked to answer 42 trivia questions from a board game. Th

Verizon [17]

Answer:

$(21.9-19.8) -1.966\sqrt{\frac{3.4^2}{200} +\frac{3.5^2}{200}}= 1.422$

$(21.9-19.8) -1.966 \sqrt{\frac{3.4^2}{200} +\frac{3.5^2}{200}}= 2.778$

And we are 95% confident that the true difference means are between $1.422 \leq \mu_1 -\mu_2 \leq 2.778$

Step-by-step explanation:

We know the following info:

$\bar X_1 = 21.9$ sample mean for group 1

$\bar X_2 = 19.8$ sample mean for group 2

$s_1 = 3.4$ sample standard deviation for group 1

$s_2 = 3.5$ sample standard deviation for group 2

$n_1 = 200$ sample size group 1

$n_2 = 200$ sample size group 2

We want to find a confidence interval for the difference of means and the correct formula to do this is:

$(\bar X_1 -\bar X_2) \pm t_{\alpha/2} \sqrt{\frac{s^2_1}{n_1} +\frac{s^2_2}{n_2}}$

Now we just need to find the critical value. The confidence level is 0.95 then the significance is $1-0.95 =0.05$ and $\alpha/2 =0.025$ . The degrees of freedom are given by:

$df= n_1 +n_2 -2= 200+200-2= 398$

The critical value for this case would be : $t_{\alpha/2}=1.966$

And replacing into the confidence interval formula we got:

$(21.9-19.8) -1.966\sqrt{\frac{3.4^2}{200} +\frac{3.5^2}{200}}= 1.422$

$(21.9-19.8) -1.966 \sqrt{\frac{3.4^2}{200} +\frac{3.5^2}{200}}= 2.778$

And we are 95% confident that the true difference means are between $1.422 \leq \mu_1 -\mu_2 \leq 2.778$

5 0

3 years ago

Find the value of 70% of ₹300

anzhelika [568]

Answer:

70% of 300 is 210

5 0

3 years ago

A scientist is studying the population growth rates of two different species of rats in the same laboratory conditions. The popu

Korolek [52]

Since, population of species A is represented by : $P=2^{x} +19$

Let us find the population of species A, at the end of week 1:

i.e., x = 1

i.e., $P(1)=2^{1} +19$

i.e., $P(1)=2 +19$

i.e., $P(1)=21$

Also, since population of species B is represented by : $P=3^{x} +18$

Let us find the population of species B, at the end of week 1:

i.e., x = 1

i.e., $P(1)=3^{1} +18$

i.e., $P(1)=3 +18$

i.e., $P(1)=21$

Thus, at the end of 1 week, species A and species B will have the same population.

Hence, option D is correct.

4 0

3 years ago

What's the answer to this question

sesenic [268]

C. 110. This is because all triangles add up to equal 180*. So you add the two angles you have and subtract from 180.

5 0

3 years ago

In order to make 6 dozen cookies, you must use 3 eggs in the batter. How many eggs would be required to make 48 dozen cookies? U

Brrunno [24]

24

Step-by-step explanation:

Well 6 times 8 is 48 so

8 times 3 is 24

7 0

3 years ago

Read 2 more answers

Solve the quadratic by factoring. x^2+17=-10x-7x 2 +17=−10x−7