Multiply the following complex numbers: (4 + 7i) (-3-1)

(21.23) A study of the effect of exposure to color (red or blue) on the ability to solve puzzles used 42 subjects. Half the subj

Cloud [144]

Answer:

There is enough statistical evidence to say that the means are different.

Step-by-step explanation:

The question is incomplete:

"The two-sample t statistic for comparing the population means has value (±0.001)."

The null and alternative hypothesis are:

$H_0: \mu_r-\mu_b=0\\\\H_1: \mu_r-\mu_b\neq0$

The level of significance is assumed to be α=0.01.

The difference of the sample means is:

$M_d=M_r-M_b=9.64-15.84=-6.20$

The standard deviation for the difference of the means is:

$s_d=\sqrt\frac{s_r^2+s_b^2}{n} } =\sqrt\frac{3.43^2+8.65^2}{21} }=\sqrt{\frac{85.59}{21} }=\sqrt{4.12} =2.03$

Then, the t-statistic is:

$t=\frac{M_d-(\mu_r-\mu_b)}{s_d} =\frac{-6.20-0}{2.03}= -3.05$

The degrees of freedom are:

$df=n_r+n_b-2=21+21-2=40$

With 40 degrees of freedom the t-critial for a significance of α=0.01 is t=±2.705.

As the t-statistic lies in the rejection region, the effect is significant and the null hypothesis is rejected.

There is enough statistical evidence to say that the means are different.

7 0

3 years ago

Help me thank you please help

weqwewe [10]

Answer:

I think 2 but sorry if I'm wrong

Step-by-step explanation:

6 0

1 year ago

If each point in the diagram can act as an endpoint, how many distinct line segments can be formed using the set of points

sdas [7]

Answer:

Option D 6 is the answer.

Step-by-step explanation:

the given points are A, D, C and B. If each point in the diagram can act as end points, we have to calculate number of distinct line segments formed.

This ca be calculated in two ways.

(1) We will form the line segments

AB, AC, AD, BC, BD, DC

Therefore 6 segments can be formed.

(2) By combination method

Number of segments = $^{4}C_{2}$

= $\frac{4!}{2!2!}=\frac{4\times 3\times 2\times 1}{(2\times 1)\times (2\times 1)}$

= $\frac{4\times 3}{2\times 3}=\frac{12}{2}$

= 6

Option D 6 is the answer.

8 0

2 years ago

Read 2 more answers

The perimeter of a rectangular

cupoosta [38]

Answer:

5 ft

Step-by-step explanation:

Since we have a rectangle, we know for sure that perimeter = double the width and double the height. Algebraically, that looks like:

P = 2W + 2H

Let's sub in the given values, P and W:

18 = 2(4) + 2H

Now, let's solve for the height, H:

18 = 8 + 2H

10 = 2H

10/2 = H

5 = H

I hope this helps!

7 0

2 years ago

Bruce is going grocery shopping. he can go to the deli, the bakery, and the dairy section. How many possibilities are there for

vodomira [7]

Answer:

1. deli, bakery, dairy;

2. deli, dairy, bakery;

3. bakery, dairy, deli;

4. bakery, deli, dairy;

5. dairy, bakery, deli;

6. dairy, deli, bakery

Step-by-step explanation:

6 possibilities

8 0

2 years ago