H - 16 ≤

Solve 7x − 2(x + 1) = 6x + 14.<br> −12<br> 12<br> −16<br> 16

Vladimir79 [104]

7x-2(x+1)=6x+14
7x-2x-2=6x+14
5x-6x=14+2
-x=16
x=-16

3 0

3 years ago

In a recent year, 304 of the approximately 300,000,000 people in the United States were struck by lightning. Estimate the prob

umka2103 [35]

Answer:

$\frac{19}{18,750,000}=0.0000010133333333$

Step-by-step explanation:

We have been given that in a recent year, 304 of the approximately 300,000,000 people in the United States were struck by lightning.

$\text{Probability}=\frac{\text{Number of favorable outcomes}}{\text{Number of possible outcomes}}$

$\text{P( A randomly selected person in the United States will be struck by lightning this year)}=\frac{304}{300,000,000}$

$\text{P( A randomly selected person in the United States will be struck by lightning this year)}=\frac{19}{18,750,000}$

$\text{P( A randomly selected person in the United States will be struck by lightning this year)}=0.0000010133333333$

Therefore, the probability that a randomly selected person in the United States will be struck by lightning this year is $\frac{19}{18,750,000}=0.0000010133333333$ .

6 0

3 years ago

Read 2 more answers

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

Triangle EFG has the following vertices E(1,2), F(4,2) and G(1,6). What are the new coordinates of triangle E’F’G’ after it is r

Fynjy0 [20]

Answer:

i dont know but

Step-by-step explanation:

DO ANYTHING FO CLOUTTTTTTTTTT

7 0

3 years ago

What is the value of the expression below when y=10? 5y+3

trasher [3.6K]

I think it is 53 that’s what i would put if i were u

7 0

3 years ago

H - 16 ≤ - 24