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Sav [38]
4 years ago
8

Ten less than half of what number is 30?

Mathematics
1 answer:
EleoNora [17]4 years ago
6 0

Answer:

x = 80

Step-by-step explanation:

Let x be the unknown number

1/2 x - 10 = 30

Add 10 to each side

1/2x -10+10 = 30+10

1/2x = 40

Multiply each side by 2

1/2x * 2 = 40*2

x = 80

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If f(x) = 2x - 1 and g(x) = x^2 - 2, find [g · f](x)<br><br> please show me how to do this
larisa [96]

Answer:

(x² -7)/(2x + 1)

Step-by-step explanation:

f(x) = 2x+1 and g(x) = x² -7

thus: (g/f)(x) = g(x)/f(x) = x² -7/2x + 1

5 0
3 years ago
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-0.5 = -4/7<br> True<br> False
taurus [48]

Answer:

Step-by-step explanation:

false

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A physical therapist wants to determine the difference in the proportion of men and women who participate in regular sustained p
Alekssandra [29.7K]

Using the z-distribution and the formula for the margin of error, it is found that:

a) A sample size of 54 is needed.

b) A sample size of 752 is needed.

In a sample with a number n of people surveyed with a probability of a success of \pi, and a confidence level of \alpha, we have the following confidence interval of proportions.

\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}

In which z is the z-score that has a p-value of \frac{1+\alpha}{2}.

The margin of error is of:

M = z\sqrt{\frac{\pi(1-\pi)}{n}}

90% confidence level, hence\alpha = 0.9, z is the value of Z that has a p-value of \frac{1+0.9}{2} = 0.95, so z = 1.645.

Item a:

The estimate is \pi = 0.213 - 0.195 = 0.018.

The sample size is <u>n for which M = 0.03</u>, hence:

M = z\sqrt{\frac{\pi(1-\pi)}{n}}

0.03 = 1.645\sqrt{\frac{0.018(0.982)}{n}}

0.03\sqrt{n} = 1.645\sqrt{0.018(0.982)}

\sqrt{n} = \frac{1.645\sqrt{0.018(0.982)}}{0.03}

(\sqrt{n})^2 = \left(\frac{1.645\sqrt{0.018(0.982)}}{0.03}\right)^2

n = 53.1

Rounding up, a sample size of 54 is needed.

Item b:

No prior estimate, hence \pi = 0.05

M = z\sqrt{\frac{\pi(1-\pi)}{n}}

0.03 = 1.645\sqrt{\frac{0.5(0.5)}{n}}

0.03\sqrt{n} = 1.645\sqrt{0.5(0.5)}

\sqrt{n} = \frac{1.645\sqrt{0.5(0.5)}}{0.03}

(\sqrt{n})^2 = \left(\frac{1.645\sqrt{0.5(0.5)}}{0.03}\right)^2

n = 751.7

Rounding up, a sample of 752 should be taken.

A similar problem is given at brainly.com/question/25694087

5 0
3 years ago
Solve for x<br> PLEASE HELP ME !!!
Oliga [24]

Answer:

360-(26x2)

=360-52

=308

15x  - 26 = 308 \\ 15x = 308 + 26 \\ 15x = 334 \\ x = 334 \div 15 \\ x = 22.27 \: or \:  \frac{334}{15}

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3 years ago
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Quien me ayuda?porfa ;-;​
asambeis [7]

I don't understand your language sorry

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3 years ago
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