What’s the correct answer for this?

Answer:

[tex]t=\frac{(43.5 -40.1)-(0)}{3.678\sqrt{\frac{1}{20}+\frac{1}{20}}}=2.923[/tex]

The degrees of freedom are

[tex]df=20+20-2=38[/tex]

And the p value is given by:

[tex]p_v =2*P(t_{38}>2.923) =0.0058[/tex]

Since the p value for this cae is lower than the significance level of 0.05 we have enough evidence to reject the null hypothesis and we can conclude that the true means for this case are significantly different

Step-by-step explanation:

When we have two independent samples from two normal distributions with equal variances we are assuming that  

[tex]\sigma^2_1 =\sigma^2_2 =\sigma^2[/tex]

And the statistic is given by this formula:

[tex]t=\frac{(\bar X_1 -\bar X_2)-(\mu_{1}-\mu_2)}{S_p\sqrt{\frac{1}{n_1}+\frac{1}{n_2}}}[/tex]

Where t follows a t distribution with [tex]n_1+n_2 -2[/tex] degrees of freedom and the pooled variance [tex]S^2_p[/tex] is given by this formula:

[tex]S^2_p =\frac{(n_1-1)S^2_1 +(n_2 -1)S^2_2}{n_1 +n_2 -2}[/tex]

The system of hypothesis on this case are:

Null hypothesis: [tex]\mu_1 = \mu_2[/tex]

Alternative hypothesis: [tex]\mu_1 \neq \mu_2[/tex]

We have the following data given:

[tex]n_1 =20[/tex] represent the sample size for group 1

[tex]n_2 =20[/tex] represent the sample size for group 2

[tex]\bar X_1 =43.5[/tex] represent the sample mean for the group 1

[tex]\bar X_2 =40.1[/tex] represent the sample mean for the group 2

[tex]s_1=4.1[/tex] represent the sample standard deviation for group 1

[tex]s_2=3.2[/tex] represent the sample standard deviation for group 2

First we can begin finding the pooled variance:

[tex]\S^2_p =\frac{(20-1)(4.1)^2 +(20 -1)(3.2)^2}{20 +20 -2}=13.525[/tex]

And the deviation would be just the square root of the variance:

[tex]S_p=3.678[/tex]

The statistic is givne by:

[tex]t=\frac{(43.5 -40.1)-(0)}{3.678\sqrt{\frac{1}{20}+\frac{1}{20}}}=2.923[/tex]

The degrees of freedom are

[tex]df=20+20-2=38[/tex]

And the p value is given by:

[tex]p_v =2*P(t_{38}>2.923) =0.0058[/tex]

Since the p value for this cae is lower than the significance level of 0.05 we have enough evidence to reject the null hypothesis and we can conclude that the true means for this case are significantly different

Using the t-distribution, as we have the standard deviation for the sample, it is found that the researcher can conclude that there is a difference between the population means at the 0.05 significance level.

At the null hypothesis, it is tested if there is no difference, that is:

[tex]H_0: \mu_1 - \mu_2 = 0[/tex]

At the alternative hypothesis, it is tested if there is a difference, that is:

[tex]H_a: \mu_1 - \mu_2 \neq 0[/tex]

For each sample, we have that they are given by

[tex]\mu_1 = 43.5, s_1 = \frac{4.1}{\sqrt{20}} = 0.9168[/tex]

[tex]\mu_2 = 40.2, s_2 = \frac{3.2}{\sqrt{20}} = 0.7155[/tex]

Hence, for the distribution of differences, the mean and the standard error are given by:

[tex]\overline{x} = \mu_1 - \mu_2 = 43.5 - 40.2 = 3.3[/tex]

[tex]s = \sqrt{s_1^2 + s_2^2} = \sqrt{0.9168^2 + 0.7155^2} = 1.163[/tex]

It is given by:

[tex]t = \frac{\overline{x} - \mu}{s}[/tex]

In which [tex]\mu = 0[/tex] is the value tested at the null hypothesis, hence:

[tex]t = \frac{\overline{x} - \mu}{s}[/tex]

[tex]t = \frac{3.3 - 0}{1.163}[/tex]

[tex]t = 2.84[/tex]

Considering a two-tailed test, as we are testing if the mean is different of a value, with a significance level of 0.05 and 20 + 20 - 2 = 38 df, the critical value is of [tex]|z^{\ast}| = 2.0244[/tex].

Since the absolute value of the test statistic is greater than the critical value, it is found that the researcher can conclude that there is a difference between the population means at the 0.05 significance level.

More can be learned about the t-distribution at https://brainly.com/question/16313918

Answer:

V = 216 cm^3

Step-by-step explanation:

The volume of a cube is given by

V = s^3 where s is the side length

V = (6)^3

V = 216 cm^3

Answer:216 cm^3

Step-by-step explanation:

In cube, the length of all sides are equal

length of side=6cm

Volume of cube=length x length x length

Volume of cube=6 x 6 x 6

Volume of cube=216

Volume of cube=216 cm^3

Answer:

A. p + q = b

D. p · q = c

Step-by-step explanation:

It's best to look at an example, such as this:

[tex]x^2 - 12x + 35[/tex]

And it's factored form is:

(x - 5) (x - 7)

As you can see, if you add -5 (p) and -7 (q), you get -12 (b). Then, if you multiply -5 (p) and -7 (q), you get 35 (c).

Answer:

A and D

Step-by-step explanation:

STOP REPORTING MY ANSWER!!

Kono Dio Da!!!

Answer:

The claim is not true

Step-by-step explanation:

We are given that A local retailer claims that the mean waiting time is less than 8 minutes.

[tex]H_0:\mu=8[/tex]

[tex]H_a:\mu<8[/tex]

A random sample of 20 waiting times has a mean of 6.3 minutes with a standard deviation of 2.1 minutes.

[tex]\bar{x}=6.3[/tex]

s = 2.1

n = 20

Since n <30 and population standard deviation is unknown

So,we will use t test

So,[tex]t=\frac{x-\mu}{\frac{s}{\sqrt{n}}}[/tex]

[tex]t=\frac{6.3-8}{\frac{2.1}{\sqrt{20}}}[/tex]

t=-3.62

α = 0.01

Degree of freedom = df=n-1=20-1=19

[tex]t_{df,\frac{\alpha}{2}}=t_{19,\frac{0.01}{2}}=2.861[/tex]

t calculated < t critical

So, we failed to reject null hypothesis

Hence the claim is not true

Answer:

74 and 27

Step-by-step explanation:

let x and y be the numbers

x + y =101........eqn 1

x - y = 47.......eqn 2

solve simultaneously

from equation 2, make x the subject

x= 47 + y........eqn 3

put eqn 3 into eqn 1

(47+y) + y = 101

47 + 2y = 101

       2y= 101 - 47

       2y=54

         y= 54/2

         y= 27

put y=27 into eqn 3

x = 47 + 27

x = 74

Answer:

12/-10

Step-by-step explanation:

Any multiple of a fraction is the equivalent of the original fraction, the only difference is that it wont be fully simplified. If we multiply the original fraction (6/-5) by 2, both the numerator and denominator, you will get 12/-10.

Answer:

12/-10

Step-by-step explanation:

6/-5

6×2= 12

-5×2=-10

12/-10

Answer:

m=4

Step-by-step explanation:

First get the equation in slope intercept form

y -4x =1

Add 4x to each side

y - 4x+4x = 4x+1

y = 4x+1

This is in the form

y = mx+b where m is the slope and b is the y intercept

The slope is 4

Parallel lines have the same slope

m =4

[insert answer here]

Step-by-step explanation:

Answer:

Step-by-step explanation:

-3x + 4y = -18

8x - 4y =   28

5x = 10

x = 2

4 - y = 7

-y = 3

y = -3

(2, -3)

The solution of the system of linear equations given is (2,-3), the correct option is C.

The system of linear equation is set of equations which have a common solution.

The equations are

-3x+4y = -18

2x-y =7

The linear equations can be solved using substitution method

y = 2x -7 from equation 2 will be substituted in equation 1

-3x +4 ( 2x -7) = -18

-3x +8x -28 = -18

5x = 10

x = 2

y = 2 * 2 -7 = -3

To know more about System of Linear Equations

https://brainly.com/question/12895249

#SPJ2

Answer:

[tex]f(x)=-5x-3[/tex].

Step-by-step explanation:

From the given machine diagram it is clear that:

[tex]f(x)=-8[/tex] at [tex]x=1[/tex]

[tex]f(x)=-13[/tex] at [tex]x=2[/tex]

[tex]f(x)=-18[/tex] at [tex]x=3[/tex]

It is clear that the value of f(x) decreasing by 5 when the value of x is increasing by 1.

Since the function changing at a constant rate, therefore it represents a linear function.

If a linear function passing through two points, then the equation of line is

[tex]y-y_1=\dfrac{y_2-y_1}{x_2-x_1}(x-x_1)[/tex]

The given linear function passes through (1,-8) and (2,-13), therefore the linear equation is

[tex]y-(-8)=\dfrac{-13-(-8)}{2-1}(x-1)[/tex]

[tex]y+8=\dfrac{-5}{1}(x-1)[/tex]

[tex]y+8=-5(x-1)[/tex]

[tex]y=-5x+5-8[/tex]

[tex]y=-5x-3[/tex]

So, the required function is [tex]f(x)=-5x-3[/tex].

Answer: .0039

Step-by-step explanation:

Answer:

4

Step-by-step explanation:

The degree is the highest power on the exponent when they are lined up from highest to lowest

The degree is 4

Answer:D

Step-by-step explanation:

(4/5)^0

4^0/5^0=1/1=1

Answer: [tex]3(3-4x+2y)[/tex]

Step-by-step explanation:

[tex]9-12x+6y[/tex]

[tex]3(3-4x+2y)[/tex]

Answer:

256÷-16=16

Step-by-step explanation:

The complete expression is 256 divided by -16 is -16

From the question, we have the following parameters that can be used in our computation:

256 divided by -16 = what

When represented as an equation, we have

Result = 256 divided by -16

Make the result the subject of the formula

So, we have

Result = 256/-16

Rewrite as

Result = -256/16

Evaluate the quotient

Result = -16

Hence, the number is -16

Read more about expressions at

https://brainly.com/question/30492964

#SPJ6

Answer:

Step-by-step explanation:

(a) 3 of the 6 numbers on the die are even, so the probability that one of them will show is 3/6 = 1/2.

__

(b) 2 of the 6 numbers on the die are less than 3, so the probability that one of them will show is 2/6 = 1/3.

Answer: right isosceles

Step-by-step explanation:

the angle at the bottom is right therefore you need to figure out the lengths of the sides to conclude if it is isosceles or scalene. because two of the sides are the same length and the other is not it is isosceles

Answer:

Step-by-step explanation: answer is 480 cubic feet. Just do 8 x 6 x 10.

Answer: t ≥ 33

Step-by-step explanation:

So the temperature has to equal to 33 or less than 33.It can't be greater than 33.

Answer:

The answer is (x+8)(x-3) .

Step-by-step explanation:

First, you have to elaborate out :

[tex] {x}^{2} + 5x - 24[/tex]

[tex] = {x}^{2} - 3x + 8x - 24[/tex]

Next, you can factor out the like terms :

[tex] {x}^{2} - 3x + 8x - 24[/tex]

[tex] = x(x - 3) + 8(x - 3)[/tex]

[tex] = (x - 3)(x + 8)[/tex]

Answer:(x-3)(x+8)

Step-by-step explanation:

x^2+5x-24

We first find two numbers whose product is -24 and whose sum is 5,the two numbers are 8 and -3,we then removed +5x from the equation and replace it with +8x-3x

x^2+8x-3x-24

We factorise

x(x+8)-3(x+8)

We factorise the like terms which is (x+8)

(x-3)(x+8)

Answer:

(x - 5)(x - 3)

Step-by-step explanation:

[tex] {x}^{2} - 8x + 15 \\ = {x}^{2} - 5x - 3x + 15 \\ = x(x - 5) - 3(x - 5) \\ = (x - 5)(x - 3) \\ \\ ac = ( - 5) (- 3) = 15 \\ a + c = - 5 - 3 = - 8[/tex]

Answer:

$42,900 a year

Step-by-step explanation:

so there are 26 bi-weeks in a year. (fun fact)

you take $1,650 and multiply that biweekly to get her annual salary.

1650*26=42,900

Answer:

D. Observational Study

Explanation:

An observational  study is one in which all the participants are subjected to a common treatment and then compared to people who did not receive the same treatment. This is the case with the students who where subjected to the same treatment; an additional rehearsal session. They are then observed by the professor and compared to those who did not participate in the experiment.  

This is also an example of a cohort observational study. A cohort observational study is one in which all the participants have a common uniting factor. They are made to undergo a treatment and then compared to those who did not receive the treatment. This type of study  is subject to bias because a positive or negative result might be because of other factors not related to the study.

Answer:

its 40

Step-by-step explanation:

i think

Answer:

The the best college to go to is the one where you feel comfortable.

Step-by-step explanation:

It is so important to understand the sence of what is actually "the best" college to go to.

You can look at that from a viriety of perspectives, and it is debatable to just go for the college which holds the highest rank on some site.

There are a lot of factors to consider, and what is generally considered the best college does not necassarilly the right one for you.

Ask your loved ones for advice and if you can take a look at yourvtop thee collages.

The the best college to go to is the one where you feel comfortable.

Answer:

3 times at 3

Step-by-step explanation:

Answer:

After tax deduction he makes $676.875  a week

Step-by-step explanation:

9.75% of 750 is 71.125

750-71.125 is 676.875

Answer: 5/13

Step-by-step explanation:

Answer:

5/13 is in simplest form, because it cannot be reduced any further.

Step-by-step explanation: 4/20 can be reduced to 1/5, 6/9 to 1/3, and 14/21 can be reduced to 2/3

Answer:

The number: 13,226

Step-by-step explanation:

1. The smallest 5-digit number possibile is: 10,000

2. The smallest 5-digit number being odd should be: 10,001

3. All factors of 6 are {1, 2, 3, 6} so that the smallest possible way to arrange these numbers would be: 11,236

4.  Now this number contains 3 prime numbers, 2 being {2 and 3}. If we were to consider another prime number, still being a factor of 6, that would be: 2. That would mean instead of the 1 being the second digit of the value 11,236 it could be 2: 12,236.

5. The digit in the thousands place (2) should be greater than the digit in the tens place (3). Let's swap these digits for now so that condition is satisfied: 13,226. 2 is the only number that has a number greater than it, besides 1, but 1 can't be a digit in the tenth place as it would make a greater 5 digit-number. Thus, provided the conditions are still satisfied, the number 13,226 is the smallest number possible.