Which expression is equivalent to 4(12+5)+3?

a product online for $299 and was charged an additional $10 for shipping and handling. The customer received a rebate of $99 and

sammy [17]

The customer payed $192.4 for the product.

8 0

3 years ago

Read 2 more answers

Suppose we are interested in analyzing the weights of NFL players. We know that on average, NFL players weigh 247 pounds with a

tigry1 [53]

Answer:

$SE= \frac{\sigma}{\sqrt{n}} = \frac{47}{\sqrt{30}}= 8.58$

$ME= 1.64 *\frac{\sigma}{\sqrt{n}} = 1.64*\frac{47}{\sqrt{30}}= 14.073$

$\bar X - ME = 237- 14.073 = 222.927$

$\bar X + ME = 237+ 14.073 = 251.073$

$n=(\frac{1.640(47)}{5})^2 =237.65 \approx 238$

So the answer for this case would be n=238 rounded up to the nearest integer

Null hypothesis: $\mu \geq 247$

Alternative hypothesis: $\mu$

$z=\frac{237-247}{\frac{47}{\sqrt{30}}}=-1.165$

$p_v =P(z$

If we compare the p value and the significance level given $\alpha=0.1$ we see that $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can't conclude that the true mean is lower than 247 at 10% of significance.

Step-by-step explanation:

For this case we have the following data given:

$\bar X =237$ represent the sample mean

$\sigma = 47$ represent the population deviation

$n =30$ represent the sample size selected

$\mu_0 = 247$ represent the value that we want to test.

The standard error for this case is given by:

$SE= \frac{\sigma}{\sqrt{n}} = \frac{47}{\sqrt{30}}= 8.58$

For the 90% confidence the value of the significance is given by $\alpha=1-0.9 = 0.1$ and $\alpha/2 = 0.05$ so we can find in the normal standard distribution a quantile that accumulates 0.05 of the area on each tail and we got:

$z_{\alpha/2}= 1.64$

And the margin of error would be:

$ME= 1.64 *\frac{\sigma}{\sqrt{n}} = 1.64*\frac{47}{\sqrt{30}}= 14.073$

The confidence interval for this case would be given by:

$\bar X - ME = 237- 14.073 = 222.927$

$\bar X + ME = 237+ 14.073 = 251.073$

The margin of error is given by this formula:

$ME=z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (a)

And on this case we have that ME =5 and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=(\frac{z_{\alpha/2} \sigma}{ME})^2$ (b)

Replacing into formula (b) we got:

$n=(\frac{1.640(47)}{5})^2 =237.65 \approx 238$

So the answer for this case would be n=238 rounded up to the nearest integer

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the true mean is lower than 247 pounds, the system of hypothesis would be:

Null hypothesis: $\mu \geq 247$

Alternative hypothesis: $\mu$

Since we know the population deviation, is better apply a z test to compare the actual mean to the reference value, and the statistic is given by:

$z=\frac{\bar X-\mu_o}{\frac{\sigma}{\sqrt{n}}}$ (1)

z-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

Calculate the statistic

We can replace in formula (1) the info given like this:

$z=\frac{237-247}{\frac{47}{\sqrt{30}}}=-1.165$

P-value

Since is a left tailed test the p value would be:

$p_v =P(z$

Conclusion

If we compare the p value and the significance level given $\alpha=0.1$ we see that $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can't conclude that the true mean is lower than 247 at 10% of significance.

5 0

3 years ago

Please help with this algebra question

zhenek [66]

We have
-2x-3y <12
For this case what you should do is to graph the following straight line:
-2x-3y = 12
Then, the solution will be the shaded region that satisfies the following inequality:
-2x-3y <12
In the shaded region you will find all the solution points.
Answer:
See attached image

7 0

3 years ago

if you were asked to express the weight in ounces of a ladybug in scientific notation, would the exponent of the 10 be positive

Nat2105 [25]

The <em><u>correct answer</u></em> is:

Negative.

Explanation:

Scientific notation is used to express very small or very large numbers.

Very small numbers are written in scientific notation using negative exponents.

Very large numbers are written in scientific notation using positive exponents.

Since a ladybug is very small, we would use the very small scientific notation, which uses negative exponents.

8 1

4 years ago

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Find the values of x and y. Show your work pls (7x-4) (4y+8) 24 and 31

abruzzese [7]

Answer:

The value of x is 5.

The value of y is 4.

Step-by-step explanation:

From the figure, the lengths of the lines with equal number of markings are equal.

So, we will have the length of 7x - 4 = 31.

We solve for 'x'.

We get: 7x = 35

⇒ x = 5

Similarly, 4y + 8 = 24

⇒ 4y = 24 - 8

⇒ 4y = 16

⇒ y = 4

Therefore, the value of x = 5 and y = 4.

Hence, the answer.

8 0

3 years ago