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3 years ago

What is 1/4 times 7/9?

Mathematics

1 answer:

denpristay [2]3 years ago

3 0

Answer:

7/36

Step-by-step explanation:

1/4 × 7/9 = 7/36 Hope that helps!

You might be interested in

Let a be a real number and n a positive integer . show that x-a is a factor of x^n- a^n

nikklg [1K]

Answer:

steps below

Step-by-step explanation:

x-a=0

x=a plug in xⁿ - aⁿ

xⁿ - aⁿ = aⁿ - aⁿ = 0

(x-a) must be a factor of xⁿ - aⁿ

6 0

3 years ago

A random sample of 20 purchases showed the amounts in the table (in $). The mean is $49.57 and the standard deviation is $20.28.

son4ous [18]

Answer:

The 98% confidence interval for the mean purchases of all customers is ($37.40, $61.74).

Step-by-step explanation:

We have that to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = \frac{1-0.98}{2} = 0.01$

Now, we have to find z in the Ztable as such z has a pvalue of $1-\alpha$ .

So it is z with a pvalue of $1-0.01 = 0.99$ , so $z = 2.325$

Now, find M as such

$M = z*\frac{\sigma}{\sqrt{n}}$

In which $\sigma$ is the standard deviation of the population and n is the size of the sample.

$M = 2.325*\frac{20.28}{\sqrt{20}} = 12.17$

The lower end of the interval is the mean subtracted by M. So it is 49.57 - 12.17 = $37.40.

The upper end of the interval is the mean added to M. So it is 49.57 + 12.17 = $61.74.

The 98% confidence interval for the mean purchases of all customers is ($37.40, $61.74).

3 0

3 years ago

Carlos dropped the phone he had received for his birthday and broke the screen. He knows he has to pay for the replacement himse

NeX [460]

Answer:

you would want B

Step-by-step explanation:

why because if you get a discount you would be able to have to not pay as much as if you dont get a discount.

7 0

3 years ago

Forces of 9 lbs and 13 lbs act at a 38º angle to each other. Find the magnitude of the resultant force and the angle that the re

fiasKO [112]

Answer: $R=20.84\ lb\quad 22.57^{\circ},15.43^{\circ}$

Step-by-step explanation:

Given

Two forces of 9 and 13 lbs acts $38^{\circ}$ angle to each other

The resultant of the two forces is given by

$\Rightarrow R=\sqrt{a^2+b^2+2ab\cos \theta}$

Insert the values

$\Rightarrow R=\sqrt{9^2+13^2+2(9)(13)\cos 38^{\circ}}\\\Rightarrow R=\sqrt{81+169+184.394}\\\Rightarrow R=\sqrt{434.394}\\\Rightarrow R=20.84\ lb$

Resultant makes an angle of

$\Rightarrow \alpha=\tan^{-1}\left( \dfrac{b\sin \theta}{a+b\cos \theta}\right)\\\\\text{Considering 9 lb force along the x-axis}\\\\\Rightarrow \alpha =\tan^{-1}\left( \dfrac{13\sin 38^{\circ}}{9+13\cos 38^{\circ}}\right)\\\\\Rightarrow \alpha =\tan^{-1}(\dfrac{8}{19.244})\\\\\Rightarrow \alpha=22.57^{\circ}$