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3 years ago

A coin weighs 5/6 ounces. Ann picked up 3 of these coins.

1 answer:

7 0

How I’d do it:
5/6 three times makes 15/6. Made into a mixed fraction is 2 3/6, which in its simplest form is 2 1/2.
When converted to ounces, assuming that 6/6 is one complete ounce, then you get 2.5 ounces.
The total weight she picked up is 2.5 ounces.

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Bob makes a drawing of a garden that has a scale of 5 cm for each meter. If the garden will be 15 m long, how long is the drawin

faust18 [17]

It would be 75 centimeters long

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3 years ago

Read 2 more answers

SAT scores are normally distributed with a mean of 1,500 and a standard deviation of 300. An administrator at a college is inter

Rama09 [41]

Answer:

The administrator should sample 968 students.

Step-by-step explanation:

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

$\alpha = \frac{1 - 0.88}{2} = 0.06$

Now, we have to find z in the Z-table as such z has a p-value of $1 - \alpha$ .

That is z with a p-value of $1 - 0.06 = 0.94$ , so Z = 1.555.

Now, find the margin of error 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.

Standard deviation of 300.

This means that $n = 300$

If the administrator would like to limit the margin of error of the 88% confidence interval to 15 points, how many students should the administrator sample?

This is n for which M = 15. So

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

$15 = 1.555\frac{300}{\sqrt{n}}$

$15\sqrt{n} = 300*1.555$

Dividing both sides by 15

$\sqrt{n} = 20*1.555$

$(\sqrt{n})^2 = (20*1.555)^2$

$n = 967.2$

Rounding up:

The administrator should sample 968 students.

5 0

3 years ago

64 POINT QUESTION<br><br> √(5-2x) - √(2-x) = 1

Ivanshal [37]

Answer:

x = 2 and x = -2

Step-by-step explanation:

The easiest way is to guess. We know that you can't have a square root of a negative number. This constrains x between negative infinity to 2. Testing 2 and -2, we see that it satisfy the equation.

The more systematic approach is shown below

$\sqrt{5-2x}-\sqrt{2-x}=1 \\\sqrt{5-2x}-\sqrt{2-x}+\sqrt{2-x}=1+\sqrt{2-x} \\\sqrt{5-2x} = 1+\sqrt{2-x}$

$5-2x=(1+\sqrt{2-x})^2\\5-2x=1+2\sqrt{2-x}+2-x\\2-x=2\sqrt{2-x}\\1-0.5x=\sqrt{2-x}\\(1-0.5x)^2=2-x\\1-x+0.25x^2=2-x\\0.25x^2-1=0\\0.25x^2 = 1\\x^2 = 4\\x = +/-2$