HELP PLEASE!! ASAP WILL MARK BRAINLIEST!! MATH!!

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

To the nearest foot, what amount of fencing is needed to surround the perimeter of the flower bed? 17 feet 33 feet 40 feet 50 fe

KATRIN_1 [288]

We have two flower beds in this example, the first has a perimeter of 100 feet, and the second has a perimeter of 180 feet

The total is 280 feet

<h3>Perimeter of Rectangle</h3>

Given Data

Dimension of the first flower bed

Length = 17 feet

Width = 33 feet

Perimeter = 2L + 2W

Perimeter = 2*17 + 2*33

Perimeter = 34 + 66

Perimeter = 100 feet

Dimension of the second flower bed

Length = 40 feet

Width = 50 feet

Perimeter = 2L + 2W

Perimeter = 2*40 + 2*50

Perimeter = 80 + 100

Perimeter = 180 feet

The total length will be 100+180 = 280 feet

Learn more about Perimeter here:

brainly.com/question/19819849

4 0

2 years ago

Simplify the expression

SashulF [63]

Answer:

1/(c - d)

Step-by-step explanation:

Multiply numerator and denominator by cd, then factor the denominator and cancel the common factor. (The result is restricted to c+d ≠ 0.)

$\displaystyle\frac{\frac{1}{c}+\frac{1}{d}}{\frac{c}{d}-\frac{d}{c}}=\frac{d+c}{c^2-d^2}\\\\=\frac{d+c}{(c-d)(d+c)}=\frac{1}{c-d}$

4 0

3 years ago

Read 2 more answers

Solve the equation below for x. <br> 500 = 25e ^ (2x)

Zigmanuir [339]

Answer:

x = i π n + log(20)/2 for n element Z

Step-by-step explanation:

Solve for x:

500 = 25 e^(2 x)

500 = 25 e^(2 x) is equivalent to 25 e^(2 x) = 500:

25 e^(2 x) = 500

Divide both sides by 25:

e^(2 x) = 20

Take the natural logarithm of both sides:

2 x = 2 i π n + log(20) for n element Z

Divide both sides by 2:

Answer: x = i π n + log(20)/2 for n element Z

7 0

3 years ago

7d^2+10 HELPPP SOVE THIS

Amanda [17]

So you just plug in the X value of the number that d represents for example if I plug in 2 for d

7(2)^2+10=38

4 0

3 years ago