Help me please asap ‘,:’

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

denpristay [2]

Answer:

(1) Correct option is B.

(2) Correct option is C.

Step-by-step explanation:

The information provided is:

$n_{1}=200,\ \bar x_{1}=22.7,\ s_{1} = 4.5\\n_{2}=200,\ \bar x_{2}=19.7,\ s_{2} = 4.3$

The (1 - α)% confidence interval for the difference between two mean is:

$CI=\bar x_{1}-\bar x_{2}\pm t_{\alpha/2, (n_{1}+n_[2}-2}\sqrt{\frac{s_{1}^{2}}{n_{1}}+\frac{s_{2}^{2}}{n_{2}} }$

The critical value of t is:

$\alpha /2=0.05/2=0.025$

degrees of freedom $=n_{1}+n_{2}-2=200+200-2=398$

$t_{\alpha/2, n_{1}+n_{2}-2}=t_{0.025, 398}=1.96$

Compute the 95% confidence interval for the difference between two mean as follows:

$CI=22.7-19.7\pm 1.96\sqrt{\frac{4.5^{2}}{200}+\frac{4.3^{2}}{200} }\\=3\pm0.8624\\=(2.1376, 3.8624)\\\approx(2.14, 3.86)$

Thus, the 95% confidence interval, (2.14, 3.86) implies that the true mean difference value is contained in this interval with probability 0.95.

Correct option is B.

The null value of the difference between means is 0.

As the value 0 is not in the interval this implies that there is a difference between the two means, concluding that priming does have an effect on scores.

Correct option is C.

4 0

3 years ago

Kelly has made 16 out of 25 free throws. the probability that she will make her next free throw is 64%. Is this an Experimental

Anna71 [15]

Well percents are probability, and probability is similar to theory. So i think its theoritical probability.

Hope this helps.

7 0

3 years ago

Apply the zero matirx: [16 -24] + [ 0 0 ]=[ x y] X=? Y=?

Ainat [17]

Answer:

x = 16

y = -24

Step-by-step explanation:

Recall that the addition of matrices is done when matrices are of the same dimension. In this case, you are in fact adding matrices of the same dimension (dimension 1x2). Recall as well that in the addition of matrices, the elements of each matrix combine only with the element located in the exact same position in the other matrix.

So for this case the first element of the first matrix "16" combines with the first element of the second matrix "0" resulting in an element of value16 + 0 =16 in the new matrix.

Equally, the second element of the first matrix "-24" combines with the second element of the second matrix, resulting in : -24 + 0 = -24.

Therefore, the matrix resultant from this addition is: [16 -24] (same form of the first matrix, which indicates that adding a zero matrix to an existing matrix will not change the first matrix.

5 0

3 years ago

X-4y= -2 3x-y=5 in y form

Mamont248 [21]

X-4y=-2
-x. -x
4y=-2-x
4y=x-(-2)
/4. /4
Y=4x+2/4

3x-y=5
-3x. -3x
-y=5-3x
-y=-3x+5
/-1. /-1
Y=3x-5

7 0

3 years ago

#4 is tough for me can you help me and explain how you got the answers.

Gnoma [55]

You put the scores in order from least to greatest, then you have to find the middle number. Now you will end up with two middle numbers you add them and divide by 2 then u have it answer.

4 0

3 years ago