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3 years ago

Find the missing number ___:7 = 12:21 A.14 B.12 C.4 D.3

1 answer:

Nadusha1986 [10]3 years ago

6 0

<span>The question is asking us to "find the missing number ___:7 = 12:21 First, let's see how similar are 7 and 21 - 21 is 7 multiplied by 3. So the gap will be filled in by something that multiplied by 3 will give us 12. So we have : x*3=12, and also: x=12/4=4, so the answer is C.4</span>

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The market and Stock J have the following probability distributions:

denis-greek [22]

Answer:

1) $E(M) = 14*0.3 + 10*0.4 + 19*0.3 = 13.9 \%$

2) $E(J)= 22*0.3 + 4*0.4 + 12*0.3 = 11.8 \%$

3) $E(M^2) = 14^2*0.3 + 10^2*0.4 + 19^2*0.3 = 207.1$

And the variance would be given by:

$Var (M)= E(M^2) -[E(M)]^2 = 207.1 -(13.9^2)= 13.89$

And the deviation would be:

$Sd(M) = \sqrt{13.89}= 3.73$

4) $E(J^2) = 22^2*0.3 + 4^2*0.4 + 12^2*0.3 =194.8$

And the variance would be given by:

$Var (J)= E(J^2) -[E(J)]^2 = 194.8 -(11.8^2)= 55.56$

And the deviation would be:

$Sd(M) = \sqrt{55.56}= 7.45$

Step-by-step explanation:

For this case we have the following distributions given:

Probability M J

0.3 14% 22%

0.4 10% 4%

0.3 19% 12%

Part 1

The expected value is given by this formula:

$E(X)=\sum_{i=1}^n X_i P(X_i)$

And replacing we got:

$E(M) = 14*0.3 + 10*0.4 + 19*0.3 = 13.9 \%$

Part 2

$E(J)= 22*0.3 + 4*0.4 + 12*0.3 = 11.8 \%$

Part 3

We can calculate the second moment first with the following formula:

$E(M^2) = 14^2*0.3 + 10^2*0.4 + 19^2*0.3 = 207.1$

And the variance would be given by:

$Var (M)= E(M^2) -[E(M)]^2 = 207.1 -(13.9^2)= 13.89$

And the deviation would be:

$Sd(M) = \sqrt{13.89}= 3.73$

Part 4

We can calculate the second moment first with the following formula:

$E(J^2) = 22^2*0.3 + 4^2*0.4 + 12^2*0.3 =194.8$

And the variance would be given by:

$Var (J)= E(J^2) -[E(J)]^2 = 194.8 -(11.8^2)= 55.56$

And the deviation would be:

$Sd(M) = \sqrt{55.56}= 7.45$

8 0

3 years ago

Solve the following quadratic equation<br>x+12x+36 - 16

Doss [256]

Answer:

x= -2, x= -10

Step-by-step explanation:

x^2 + 12x + 36 = 16

Began by setting this quadratic equation to 0. To do this, in this equation you must subtract.

x^2+12x+20=0

Next, we plug this into the quadratic formula, where a in this case is 1(there is nothing in front of x^2), b is equaled to 12(there is a 12 as the coeefficient of 12x), and c is equaled to 20.

The quadratic formula is as goes:

(-b+-(this means plus or minus)√b^2-4ac)/(2a)

After pluggin in and simplifying, the answer is x= -2 and x= -10

4 0

3 years ago

A recent study at UGA (March 5, 2008) suggests that students with cell phones may take more risks than students that do not have

Ira Lisetskai [31]

Answer:

(a) -2.8

b) (1) Reject H0: p = 0.50 in favor of HA: p < 0.50; there is sufficient evidence to conclude that less than half of all UGA female students who, if they had a cell phone, would be willing to walk somewhere after dark that they would normally not go.

Step-by-step explanation:

The test statistic is:

$z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}$

In which X is the sample mean, $\mu$ is the value tested at the null hypothesis, $\sigma$ is the standard deviation and n is the size of the sample.

H0: p = 0.50

This means that:

$\mu = 0.5, \sigma = \sqrt{0.5*0.5} = 0.5$

In a random sample of 305 UGA female students, 128 responded that, if they had a cell phone, they would be willing to walk somewhere after dark that they would normally not go.

This means that $n = 305, X = \frac{128}{305} = 0.4197$

a) Value of the test statistic:

$z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}$

$z = \frac{0.4197 - 0.5}{\frac{0.5}{\sqrt{305}}}$

$z = -2.8$

Pvalue:

We are testing the hypothesis that the proportion is less than 0.5, which means that the pvalue of the test is the pvalue of z = -2.81.

Looking at the z-table, z = -2.8 has a pvalue of 0.0026

(b) What is the correct conclusion for this hypothesis test at the 0.05 level of significance?

0.0026 < 0.05, which means that we reject the null hypothesis, that the proportion is 0.5, and accept the alternate hypothesis, that the proportion is less than 0.5, option (1).

6 0

3 years ago

What is 35% of the 80 letter

lions [1.4K]

Answer:

35% of 80 is 28.

Step-by-step explanation:

7 0

3 years ago

Read 2 more answers

Help plz will give brainliest

Anvisha [2.4K]

Answer:

4 the

Step-by-step explanation:

hope that helps because it is the inequality

5 0

3 years ago