Ask question

Ask question

All categories

2 years ago

7

The sample consisted of 50 night students, with a sample mean GPA of 3.02 and a standard deviation of 0.08, and 25 day students,

with a sample mean GPA of 3.04 and a standard deviation of 0.06. The test statistic is:

1 answer:

bulgar [2K]2 years ago

7 0

Answer: The test statistic is t= -0.90.

Step-by-step explanation:

Since we have given that

n₁ = 50

n₂ = 25

$\bar{x_1}=3.02\\\\\bar{x_2}=3.04\\\\\sigma_1=0.08\\\\\sigma_2=0.06$

So, s would be

$s=\sqrt{\dfrac{n_1\sigma_1^2+n_2\sigma_2^2}{n_1+n_2-2}}\\\\s=\sqrt{\dfrac{50\times 0.08^2+25\times 0.06^2}{50+25-2}}\\\\s=0.075$

So, the value of test statistic would be

$t=\dfrac{\bar{x_1}-\bar{x_2}}{s(\dfrac{1}{n_1}+\dfrac{1}{n_2})}\\t=\dfrac{3.02-3.04}{0.074(\dfrac{1}{50}+\dfrac{1}{25})}\\\\t=\dfrac{-0.04}{0.074(0.02+0.04)}\\\\t=\dfrac{-0.04}{0.044}\\\\t=-0.90$

Hence, the test statistic is t= -0.90.

You might be interested in

Pls Help! It would be very much appreciated, Thx!

Fofino [41]

Answer:

A. 30 two-point questions and 10 four-point questions

Step-by-step explanation:

30 multiplied by 2 equals 60

10 multiplied by 4 equals 40

60 plus 40 equals 100 points which is the amount of points the test is worth as stated i the question.

30 plus 10 equals 40, which is the total amount of questions in the test as stated in the question.

5 0

2 years ago

In recent commercials Toyota claimed that 80% of its vehicles sold in the past 20 years are still on the road. You work for an a

Anvisha [2.4K]

Answer:

Step-by-step explanation:

We have to perform one sample proportion test. To do so we have to proceed through following steps.

(1) We have to collect data about vehicle sales in last 20 years.

(2) Using random number table or random number generator or otherwise we have to select sample of vehicles from the list of sale. In this step, we have to keep an eye on the fact that sample is to be selected from all years (all of 20). Using stratified random sampling by dividing vehicles sold over different years is an effective way to do so. That means, we may divide vehicles sold into 20 homogeneous strata over 20 years and select sample from each strata.

(3) After selecting sample of vehicles we have to communicate to corresponding vehicle owners to gather information about that particular vehicle.

(4) We have to note number of vehicles which are still on the road.

Suppose, we have selected n vehicles as sample and after communicating we found that \tiny r of those are still on the road.

We have to test for null hypothesis $H_0:p=0.80$

against the alternative hypothesis $H_1 \neq 0.80$

Our test statistic is given

$z=\frac{\hat p - p_0}{\sqrt{p_0(1-p_0)/n} }$

here,

$\hat p =\frac{r}{n}$

$p_0 =0.80$

$z=\frac{r/n-0.80\sqrt{n} }{0.40} \\\\=2.5(\frac{r}{n} -0.8)\sqrt{n}$

We then calculate corresponding p-value.

We reject our null hypothesis if $\text{p-value}$ , level of significance.

According to our obtained p-value and level of significance we proceed to certain conclusion.

8 0

2 years ago

This is correct right?

lubasha [3.4K]

Answer:

Yes, it is not a diameter

Step-by-step explanation:

It's going through the circle (sphere) which makes it a diameter

I and D are not going straight through the middle

6 0

2 years ago

Read 2 more answers

Express the quotient of z1 and z2 in standard form given that <img src="https://tex.z-dn.net/?f=z_%7B1%7D%20%3D%20-3%5Bcos%28%5C

Lesechka [4]

Answer:

Solution : $-\frac{3}{4}-\frac{3}{4}i$

Step-by-step explanation:

$-3\left[\cos \left(\frac{-\pi }{4}\right)+i\sin \left(\frac{-\pi \:}{4}\right)\right]\:\div \:2\sqrt{2}\left[\cos \left(\frac{-\pi \:\:}{2}\right)+i\sin \left(\frac{-\pi \:\:\:}{2}\right)\right]$

Let's apply trivial identities here. We know that cos(-π / 4) = √2 / 2, sin(-π / 4) = - √2 / 2, cos(-π / 2) = 0, sin(-π / 2) = - 1. Let's substitute those values,

$\frac{-3\left(\frac{\sqrt{2}}{2}-\frac{\sqrt{2}}{2}i\right)}{2\sqrt{2}\left(0-1\right)i}$

= $-3\left(\frac{\sqrt{2}}{2}-\frac{\sqrt{2}}{2}i\right)$ ÷ $2\sqrt{2}\left(0-1\right)i$

= $3\left(-\frac{\sqrt{2}i}{2}+\frac{\sqrt{2}}{2}\right)$ ÷ $-2\sqrt{2}i$

= $\frac{3\left(1-i\right)}{\sqrt{2}}$ ÷ $2\sqrt{2}i$ = $-3-3i$ ÷ $4$ = $-\frac{3}{4}-\frac{3}{4}i$

As you can see your solution is the last option.

3 0

2 years ago

Help on hw NEED ASAP WILL SEND 90$

andriy [413]

How do I need help like fr

8 0

2 years ago

Read 2 more answers