Use the diagram and cosine function to find the value of x.

A coin is tossed 20 times. It lands on heads 9 times. What is the P(H) according to your experiment? Write your answer as a frac

Mama L [17]

Answer:

$\frac{9}{20}=0.45=45$ %

Step-by-step explanation:

Probability is found by first forming a fraction where the numerator represents the number of desired outcomes and the denominator represents the total number of outcomes. In this case, the desired outcomes is the amount of times the coin lands on heads (9) and the total outcomes is the number of times the coin is tossed (20):

$\frac{9}{20}$

Divide numerator by denominator to get a decimal: 9÷20= 0.45

Multiply the decimal by 100 to get a percent: 0.45 x 100 = 45%

8 0

3 years ago

A rectangular garden has an area of 22 square feet. If its length is 7 feet less than twice its width, find the dimensions of t

DedPeter [7]

Answer: Width is 5.5 ft, length is 18 ft

7 0

3 years ago

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

Factor the expression using the GCF.<br> 60 – 36 =

Ivanshal [37]

Answer

12 (5 - 3)

Step-by-step explanation:

The greatest common factor is the largest number that will divide both numbers evenly. As an example, 6 is a common factor because it divides both 60 and 36. However, it is not the greatest common factor.

If I break 60 into it's prime factors, I would get 2 * 2 * 3 * 5.

If I break 36 into it's prime factors, I would get 2 * 2 * 3 * 3.

The two number have the factors, 2, 2, and 3 in common.

The greatest common factor is then: 2 * 2 * 3, or 12.

The expression can be factored as: 12 ( 5 - 3)

6 0

3 years ago

This is a proportion. What is the value of X?

Verizon [17]

Answer:

x = 15 or x = - $\frac{2}{5}$

Step-by-step explanation:

Cross- multiplying gives

(14x + 6)(17x + 5) = 9x(27x + 11) ( expanding factors )

238x² + 172x + 30 = 243x² + 99x

rearrange into standard form : ax² + bx + c = 0

5x² - 73x - 30 = 0 ← in standard form

consider the factors of the product 5 × - 30 = - 150 which sum to the coefficient of the x-term (- 73 )

the factors are - 75 and + 2

Use these factors to split the middle term

5x² - 75x + 2x - 30 = 0 ( factor by grouping )

5x(x - 15) + 2(x - 15) = 0 ← take out the factor (x - 15)

(x - 15)(5x + 2) = 0

equate each factor to zero and solve for x

x - 15 = 0 ⇒ x = 15

5x + 2 = 0 ⇒ x = - $\frac{2}{5}$

7 0

3 years ago