Graph identify the solution. y =-3/5x-3. y=3

An SRS of 350 high school seniors gained an average of x¯=21 points in their second attempt at the SAT Mathematics exam. Assume

Lynna [10]

Answer:

a) $21-2.58\frac{52}{\sqrt{350}}=13.83$

$21+2.58\frac{52}{\sqrt{350}}=28.17$

So on this case the 99% confidence interval would be given by (13.83;28.17)

b) $ME=2.58\frac{52}{\sqrt{350}}=7.17$

c) $ME=2.58\frac{52}{\sqrt{100}}=13.42$

d) D. Decreasing the sample size increases the margin of error, provided the confidence level and population standard deviation remain the same.

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

Part a

$\bar X=21$ represent the sample mean

$\mu$ population mean (variable of interest)

$\sigma=52$ represent the population standard deviation

n=350 represent the sample size

99% confidence interval

The confidence interval for the mean is given by the following formula:

$\bar X \pm z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (1)

Since the Confidence is 0.99 or 99%, the value of $\alpha=0.01$ and $\alpha/2 =0.005$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-NORM.INV(0.005,0,1)".And we see that $z_{\alpha/2}=2.58$

Now we have everything in order to replace into formula (1):

$21-2.58\frac{52}{\sqrt{350}}=13.83$

$21+2.58\frac{52}{\sqrt{350}}=28.17$

So on this case the 99% confidence interval would be given by (13.83;28.17)

Part b

The margin of error is given by:

$ME=2.58\frac{52}{\sqrt{350}}=7.17$

Part c

The margin of error is given by:

$ME=2.58\frac{52}{\sqrt{100}}=13.42$

Part d

As we can see when we reduce the sample size we increase the margin of error so the best option for this case is:

D. Decreasing the sample size increases the margin of error, provided the confidence level and population standard deviation remain the same.

6 0

3 years ago

Help me with this problem please

gavmur [86]

Answer:

7 yards

Step-by-step explanation:

the absolute value of -2 and 2/3- 51/3 is 7

6 0

2 years ago

the function f(x)= sqrt x is translated left 5 units and up 3 units to create the function g(x). what is the domain of g(x)?

Zinaida [17]

Answer:

x ≥ -5

Step-by-step explanation:

If we have a translation to left c units, we write " x + c " in the function, and

If we have a translation to right c units, we write " x - c" in the function

If we have vertical translation up b units, we "add b to the function", and

If we have vertical translation down b units, we "subtract b to the function"

The parent function is $f(x)=\sqrt{x}$

Since translation left 5 units and up 3 units, we can write:

$f(x)=\sqrt{x+5} + 3$

The domain is affected by the square root sign and we know the number under the square root CANNOT be negative, so we can say:

x + 5 ≥ 0

x ≥ -5

This is the domain.

3 0

3 years ago

Read 2 more answers

What is the quotient of 2/5 divided by 3/7 A. 15/14 B. 14/15 C. 35/6 D. 6/36

STALIN [3.7K]

Answer:

$= { \tt{ \frac{2}{5} \div \frac{3}{7} }} \\ \\ = { \tt{ \frac{2}{5} \times \frac{7}{3} }} \\ \\ = { \underline{ \tt{ \: \: \frac{14}{15} \: \: }}}$

Answer: B

8 0

2 years ago

Read 2 more answers

On a coordinate plane, what is the distance between the points at (1,9) and the point (4, 9)?

sammy [17]

If you draw out a coordinate plane you will see that they , on their Y access, are both nine witch means that they a horizontal line so all you have to do is subtract the x access witch is 3.

hope this helped

4 0

3 years ago