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3 years ago

I’m so confused with this!!!

Mathematics

1 answer:

Lyrx [107]3 years ago

3 0

When you multiply a vector by a scalar, you distribute the scalar to the vector's components:

$k\langle a,b\rangle=\langle ka,kb\rangle$

In this case,

$\mathbf u=\langle25,-30\rangle\implies-\dfrac25\mathbf u=\langle-10,12\rangle$

so the answer is G.

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What do u think the answer is !!

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4 years ago

Suppose you are asked to take a sample of men and women in order to measure their emotional IQ. The emotional IQ scale that you

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Answer:

The 99% confidence interval for the scores of men is (64.406,75.594).

The 99% confidence interval for the scores of women is (73.609,90.391).

Step-by-step explanation:

We have the standard deviations for the sample, which means that the t-distribution will be used to solve this question.

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 25 - 1 = 24

99% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 24 degrees of freedom(y-axis) and a confidence level of $1 - \frac{1 - 0.99}{2} = 0.995$ . So we have T = 2.797.

For men:

Standard deviation of 10.

The margin of error is:

$M = T\frac{s}{\sqrt{n}} = 2.797\frac{10}{\sqrt{25}} = 5.594$

In which s is the standard deviation of the sample and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 70 - 5.594 = 64.406

The upper end of the interval is the sample mean added to M. So it is 70 + 5.594 = 75.594

The 99% confidence interval for the scores of men is (64.406,75.594).

For women:

Standard deviation of 15.

The margin of error is:

$M = T\frac{s}{\sqrt{n}} = 2.797\frac{15}{\sqrt{25}} = 8.391$

In which s is the standard deviation of the sample and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 82 - 8.391 = 73.609

The upper end of the interval is the sample mean added to M. So it is 82 + 8.391 = 90.391

The 99% confidence interval for the scores of women is (73.609,90.391).

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3 years ago

If y varies directly with x and y = 2 when x = 10, then what is the value of y when x = 40? A. 8 B. 45 C. 200 D. 320

Leto [7]

Answer:

Step-by-step explanation:

given that y varies directly with x then the equation relating them is

y = kx ← k is the constant of variation

to find k use the given condition y = 2 when x = 10

k = $\frac{y}{x}$ = $\frac{2}{10}$ = $\frac{1}{5}$

y = $\frac{1}{5}$ x ← equation of variation

when x = 40, then

y = $\frac{1}{5}$ × 40 = 8 → A

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