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3 years ago

Help i dont understand how to multiply fractions

2 answers:

8 0

So, what you do is 
numerator x numerator (top x top) =
and then,
denominator x denomiator (bottom x bottom) =

Hope I've helped.

Nataly_w [17]3 years ago

5 0

Just multiply the tops together and the bottoms together :)

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Simplify the expression the root of negative sixteen all over the quantity of three minus three i plus the quantity of one minus

aliya0001 [1]

The first step is to multiply the fraction by (3 +3i) / (3 +3i) to delete the i terms from the denominator:

$\frac{ \sqrt{-16} }{3-3i} . \frac{3+31}{3+3i} +1-2i= \frac{4i(3+3i)}{9+9} +1-2i= \frac{12i-12}{18} +1-2i=$

$\frac{12i-12+18-36i}{18} = \frac{6-24i}{18} = \frac{1}{3} - \frac{4}{3} i$

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3 years ago

What is a reflex angle?

jarptica [38.1K]

A reflex angle is the larger angle, it’s always more than 180* (half a circle) but less then 360* (a full circle).

5 0

3 years ago

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Heather opened a lemonade stand on her street. It costs her $5.25 to buy the supplies each day, and she sells lemonade for $1.50

victus00 [196]

Answer:

around 66.66

Step-by-step explanation:

hope this helps

6 0

3 years ago

Read 2 more answers

In 2002, the mean age of an inmate on death row was 40.7 years with a standard deviation of 9.6 years according to the U.S. Depa

marissa [1.9K]

Answer:

The 95% confidence interval for the current mean age of death-row inmates is between 42.23 years and 35.57 years.

Step-by-step explanation:

The confidence interval of the mean is given by the next formula:

$\\ \overline{x} \pm z_{1-\frac{\alpha}{2}}\frac{\sigma}{\sqrt{n}}$ [1]

We already know (according to the U.S. Department of Justice):

The (population) standard deviation for this case (mean age of an inmate on death row) has a standard deviation of 9.6 years ( $\\ \sigma = 9.6$ years).
The number of observations for the sample taken is $\\ n = 32$ .
The sample mean, $\\ \overline{x} = 38.9$ years.

For $\\ z_{1-\frac{\alpha}{2}}$ , we have that $\\ \alpha = 0.05$ . That is, the level of significance $\\ \alpha$ is 1 - 0.95 = 0.05. In this case, then, we have that the z-score corresponding to this case is:

$\\ z_{1-\frac{\alpha}{2}} = z_{1-\frac{0.05}{2}} = z_{1-0.025} = z_{0.975}$

Consulting a cumulative standard normal table, available on the Internet or in Statistics books, to find the z-score associated to the probability of, $\\ P(z$ , we have that $\\ z = 1.96$ .

Notice that we supposed that the sample is from a population that follows a normal distribution. However, we also have a value for n > 30, and we already know that for this result the sampling distribution for the sample means follows, approximately, a normal distribution with mean, $\\ \mu$ , and standard deviation, $\\ \sigma_{\overline{x}} = \frac{\sigma}{\sqrt{n}}$ .

Having all this information, we can proceed to answer the question.

Constructing the 95% confidence interval for the current mean age of death-row inmates

To construct the 95% confidence interval, we already know that this interval is given by [1]:

$\\ \overline{x} \pm z_{1-\frac{\alpha}{2}}\frac{\sigma}{\sqrt{n}}$

That is, we have:

$\\ \overline{x} = 38.9$ years.

$\\ z_{1-\frac{\alpha}{2}} = 1.96$

$\\ \sigma = 9.6$ years.

$\\ n = 32$

Then

$\\ 38.9 \pm 1.96*\frac{9.6}{\sqrt{32}}$

$\\ 38.9 \pm 1.96*\frac{9.6}{5.656854}$

$\\ 38.9 \pm 1.96*1.697056$

$\\ 38.9 \pm 3.326229$

Therefore, the Upper and Lower limits of the interval are:

Upper limit:

$\\ 38.9 + 3.326229$

$\\ 42.226229 \approx 42.23$ years.

Lower limit:

$\\ 38.9 - 3.326229$

$\\ 35.573771 \approx 35.57$ years.

In sum, the 95% confidence interval for the current mean age of death-row inmates is between 42.23 years and 35.57 years.

Notice that the "mean age of an inmate on death row was 40.7 years in 2002", and this value is between the limits of the 95% confidence interval obtained. So, according to the random sample under study, it seems that this mean age has not changed.

7 0

3 years ago

Write an expression equivalent to (6x + 4y) – 2y by combining like terms. Enter the numbers in the boxes

raketka [301]

6x +2y

Solution:

Given expression is (6x + 4y) –2y.

To find the equivalent expression for the given expression.

⇒ (6x + 4y) –2y

⇒ 6x + 4y –2y

Combine like terms together.

⇒ 6x + (4y –2y)

⇒ 6x + 2y

6x +2y is equivalent to (6x + 4y) –2y.

Hence, the expression equivalent to (6x + 4y) –2y is 6x + 2y.

5 0

3 years ago