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3 years ago

Ooooooooof I need help

Mathematics

1 answer:

snow_lady [41]3 years ago

6 0

Answer:

a) x = -1 and y = -10

Step-by-step explanation:

The first part says find the value of y when the value of x is -3. Then the second part of the question is to find the value of x when the value of y is 2.

so lets solve part a)

$y=6x+8\\y=6(-3)+8\\y=-18+8\\y=-10\\\\Now\ when\ y=2\ find\ x\ \\y=6x+8\\2=6x+8\\2-8=6x\\-6=6x\\-6/6=x\\-1=x\\$

So answer to part a is x = -1 and y = -10

similarly try the other parts.

You might be interested in

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

Use the drawing tools to form the correct answer on the provided graph.

4vir4ik [10]

Answer: (0,1), (1,0)

Step-by-step explanation:

plug in a number for y.

ex) x=0 y=1

y=-x + 1

1= -0 + 1

1=0 + 1

5 0

2 years ago

A card is drawn from a standard deck of 52 cards. Find the probability of drawing red card or a face card

nata0808 [166]

Answer:

12/104 or around 11% chance

Step-by-step explanation:

This is because there is a total of 26 red cards (1/2) and a total of 12 face cards (12/52). So, you multiply 1/2 x 12/52 and get 12/104 or around 11% chance

8 0

3 years ago

Three cards are drawn from a standard deck of 52 cards without replacement. Find the probability that the first card is an ace,

MrRissso [65]

Answer:

$4.82\cdot 10^{-4}$