PLEASE HELP ME ASAP!!! WILL MAKE YOU BRAINLIEST!!!!

I will never get the hang of these questions help

jeyben [28]

First term is -7, so a_1 = -7

To get the next term, we add on 4. We can see this if we subtract like so
d = (2nd term) - (1st term) = (-3) - (-7) = -3+7 = 4

So d = 4 is the common difference.

Apply a_1 = -7 and d = 4 to get...
a_n = a_1 + d*(n-1)
a_n = -7 + 4*(n-1)
a_n = -7 + (n-1)*4

Answer: Choice A

4 0

3 years ago

A programmer plans to develop a new software system. In planning for the operating system that he will use, he needs to estimat

Vedmedyk [2.9K]

Using the z-distribution, we have that:

a) A sample of 601 is needed.

b) A sample of 93 is needed.

c) A. Yes, using the additional survey information from part (b) dramatically reduces the sample size.

In a sample with a number n of people surveyed with a probability of a success of $\pi$ , and a confidence level of $\alpha$ , we have the following confidence interval of proportions.

$\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}$

In which z is the z-score that has a p-value of $\frac{1+\alpha}{2}$ .

The margin of error is:

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

95% confidence level, hence $\alpha = 0.95$ , z is the value of Z that has a p-value of $\frac{1+0.95}{2} = 0.975$ , so $z = 1.96$ .

For this problem, we consider that we want it to be within 4%.

Item a:

The sample size is <u>n for which M = 0.04.</u>

There is no estimate, hence $\pi = 0.5$

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

$0.04 = 1.96\sqrt{\frac{0.5(0.5)}{n}}$

$0.04\sqrt{n} = 1.96\sqrt{0.5(0.5)}$

$\sqrt{n} = \frac{1.96\sqrt{0.5(0.5)}}{0.04}$

$(\sqrt{n})^2 = \left(\frac{1.96\sqrt{0.5(0.5)}}{0.04}\right)^2$

$n = 600.25$

Rounding up:

A sample of 601 is needed.

Item b:

The estimate is $\pi = 0.96$ , hence:

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

$0.04 = 1.96\sqrt{\frac{0.96(0.04)}{n}}$

$0.04\sqrt{n} = 1.96\sqrt{0.96(0.04)}$

$\sqrt{n} = \frac{1.96\sqrt{0.96(0.04)}}{0.04}$

$(\sqrt{n})^2 = \left(\frac{1.96\sqrt{0.96(0.04)}}{0.04}\right)^2$

$n = 92.2$

Rounding up:

A sample of 93 is needed.

Item c:

The closer the estimate is to $\pi = 0.5$ , the larger the sample size needed, hence, the correct option is A.

For more on the z-distribution, you can check brainly.com/question/25404151

8 0

2 years ago

1-4y^2 = 0<br> Solve the equation

Romashka [77]

Answer: y = 1/2 or y = -1/2

Step-by-step explanation:

First move the 1 to the side with the 0

-4y^2 = -1 // -1 because when you move a number to the other side of the equation you have to multiply -1

Then divide by -4 on each side

y^2 = 1/4

square root each side

|y| = 1/2 // sq rt y^2 becomes an absolute value because when you square root a square it automatically becomes an absolute value

so the answer would be y = 1/2 or -1/2

to check just put it into the equation as y. Both work.

4 0

2 years ago

Read 2 more answers

Shea earns $8 per hour for the first 40 hours she works in a week. For any additional hours after that, she earns $12 per hour f

Ede4ka [16]

Answer: The answer is 5 but all of them are five but on the number line it’s going to the right with no fill in, it’s just a circle going to the right. Also it gives you a clue it says more than meaning greater than so it’s going this way > but the line is going this way 0———————-> on the number line with no black fill in.

Step-by-step explanation:

8 0

3 years ago

Read 2 more answers

U guys are mean and never answer my questions, like i paid for no one to answer my question

Sav [38]

Answer:

Step-by-step explanation:

You have no grounds for making a statement like that. There are a variety of reasons why you might not get immediate answers. Be patient.

I will do the second part of this question (finding the first three numbers):

a(4) = a(3)*(-3) + 2 = -148, so a(3)*(-3) = -150 and a(3) = -50

a(3) = 50

a(2) = a(3)*(-3) + 2 = 50, so -3*a(3) = 48 and a(d) = -16

a(1) = a(2)*(-3) + 2 = -16, so a(2)*(-3) = -18 and a(1) = 6

The procedure for finding a(5), a(6) and a(7) is exactly the same.

3 0

3 years ago