Please help me in so confused

MissTica

There isn't a picture to help you with.

8 0

3 years ago

A professor claims that his students' average score on the first exam of the semester is different than the average score on the

Marta_Voda [28]

Answer:

$t=\frac{\bar d -0}{\frac{s_d}{\sqrt{n}}}=0.704$

$p_v = 2*P(t_{7} >0.704)=0.504$

So the p value is higher the significance level given 0.1, so then we can conclude that we FAIL to reject the null hypothesis that the difference mean between after and before score is equal 0. So then we don't have enough evidence to say that the score for the second exam is different than the score for the first exam.

Step-by-step explanation:

Previous concepts

A paired t-test is used to compare two population means where you have two samples in which observations in one sample can be paired with observations in the other sample. For example if we have Before-and-after observations (This problem) we can use it.

Let put some notation

x=test value before (first exam) , y = test value after (second exam)

The system of hypothesis for this case are:

Null hypothesis: $\mu_y -\mu_x =0$

Alternative hypothesis: $\mu_y -\mu_x \neq 0$

The first step is calculate the difference $d_i=y_i-x_i$

The statistic given by :

$t=\frac{\bar d -0}{\frac{s_d}{\sqrt{n}}}=0.704$

The next step is calculate the degrees of freedom given by:

$df=n-1=8-1=7$

Now we can calculate the p value, since we have a left tailed test the p value is given by:

$p_v = 2*P(t_{7} >0.704)=0.504$

So the p value is higher the significance level given 0.1, so then we can conclude that we FAIL to reject the null hypothesis that the difference mean between after and before score is equal 0. So then we don't have enough evidence to say that the score for the second exam is different than the score for the first exam.

5 0

3 years ago

Jim Hunter has decided to retire to Florida in 10 years. What amount should Jim invest today so that he'll be able to withdraw $

ipn [44]

The following formula is applicable;
A=P(1+r)^n

Where,
A = Total amount accrued after 10 years (this is the amount from which the yearly withdrawals will be made from for the 30 years after retirement)
P=Amount invested today
r= Annual compound interest for the 10 years before retirement
n= Number of years the investments will be made.

Therefore,
A= Yearly withdrawals*30 years = $25,000*30 = $750,000
r= 9% = 0.09
n= 10 years

P= A/{(1+r)^n} = 750,000/{(1+0.09)^10} = $316,808.11
Therefore, he should invest $316,808.11 today.

7 0

4 years ago

Please help me(20 points will give brainliest!!!)

goblinko [34]

Answer:

A. Vertex is ( -1, 16)

B. Do they mean y-intercept for vertical intercept? That is (0,14)

C. X-intercepts are

(-3.838, 0) and (1.828, 0)

Step-by-step explanation:

plug the equation into desmos. It will graph and give you the info.

To find y-int, plug in 0 for x. This gives you the point 0, 14.

You can also use the quadratic equation to find the x-intercepts.

6 0

2 years ago

Read 2 more answers

A Car accelerates from 4 m/s to 16 m/s in 4 seconds. What is the car's

Amiraneli [1.4K]

Answer

1 m/s^2

Step-by-step explanation:

5 0

3 years ago