What is the amplitude of this function f (2) ?

How many women must be randomly selected to estimate the mean weight of women in one age group? We want 90% confidence that the

ki77a [65]

Answer:

155 women must be randomly selected.

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:

$\alpha = \frac{1 - 0.9}{2} = 0.05$

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 pvalue of $1 - 0.05 = 0.95$ , so Z = 1.645.

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.

The population standard deviation is known to be 28 lbs.

This means that $\sigma = 28$

We want 90% confidence that the sample mean is within 3.7 lbs of the populations mean. How many women must be sampled?

This is n for which M = 3.7. So

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

$3.7 = 1.645\frac{28}{\sqrt{n}}$

$3.7\sqrt{n} = 1.645*28$

$\sqrt{n} = \frac{1.645*28}{3.7}$

$(\sqrt{n})^2 = (\frac{1.645*28}{3.7})^2$

$n = 154.97$

Rounding up:

155 women must be randomly selected.

4 0

3 years ago

Can someone please help me I’ll give brilliant thingy

cricket20 [7]

Answer:

Yes, the shapes are similar. Note, the angles are equivalent and the sides are scales of each other satisfying the requirements for similarly.

Step-by-step explanation:

For a shape to be similar there are two conditions that must be met. (1) Must have equivalent angles (2) Sides must be related by a scalar.

In the two triangles presented, the first condition is met since each triangle has three angles, 90-53-37.

To test if the sides are scalar, each side must be related to a corresponding side of the other triangle with the same scalar.

9/6 = 3/2

12/8 = 3/2

15/10 = 3/2

Alternatively:

6/9 = 2/3

8/12 = 2/3

10/15 = 2/3

Since the relationship of the sides is the scalar 3/2 (Alternatively 2/3), then we can say the triangles meet the second condition.

Given that both conditions are satisfied, then we can say these triangles are similar.

Note, this is a "special case" right triangle commonly referred to as a 3-4-5 right triangle.

Cheers.

8 0

2 years ago

Find an expression for the perimeter of rectangle ABCD. Use the formula P= 2l + 2w.

natita [175]

Answer:

(b)

P = [4(4a + 3b]/(2a + b)

Step-by-step explanation:

P = 2L + 2W

P = [2(5a + 4b) + 2(3a + 2b)]/(2a + b)

P = [10a + 8b + 6a + 4b]/(2a + b)

P = [16a + 12b]/(2a + b)

P = [4(4a + 3b]/(2a + b)

3 0

3 years ago

What is -4(x+3)=16-4x

nignag [31]

Answer:

There is no solution

Step-by-step explanation:

-4(x+3)=16-4x

expand

−4x−12=16−4x

cancel out

−12=16

because −12=16 is false there is no solution.

Hope this helps :)

8 0

2 years ago

12. The Opera is collecting monies in advance for ticket sales. The tickets cost $17.50 each.

Debora [2.8K]

Answer:

The number of tickets they have sold in advance are summed up with the following equation and solution:

Equation: $\frac{6842.50}{17.50}$ [the final answer should be in dollars]

Solution: The Opera sold 391 tickets in advance.

Step-by-step explanation:

First: Review some background information:

Let's see what the problem gives us to answer it. I'll bold out the important parts:

The Opera is collecting monies in advance for ticket sales. The tickets cost $17.50 each. If they have collected $6842.50 already, then how many tickets have they sold in advance?

We know how much the tickets cost and how much money they have earned from selling tickets, we can find out how much tickets they have sold.

Second: Solve the problem:

We can solve this problem using many ways, but I'm just going to pick one. We will use proportions to answer this. Now thoughts might be going through your head like this: What is this guy saying? What in the world is proportions? Well hopefully you learn from this example (Please don't take offense if you <em>do</em> know how to do proportions).

First we set up two fractions. One ticket costs $17.50, so we will use it to set up our first fraction: $\frac{1}{17.50}$ . We don't know how many tickets all together cost $6842.50 so we will use the variable: x. Now, we can set up our second fraction. x tickets costs $6842.50 so our second fraction will be: $\frac{x}{6842.50}$ . Now we must use cross multiplication. We multiply the numerator of the first fraction times the denominator of the second fraction, and then we multiply the denominator o the first fraction times the numerator of the second fraction. That's what we would do usually. But now, since we have a variable, we must use cross multiplication to solve for this variable. So we multiply the the numerator of the first fraction times the denominator of the other fraction and then we divide that answer times the denominator of the first fraction (You don't have to set it up like this).So let's solve this question:

$\frac{1}{17.50}$ $\frac{x}{6842.50}$

1 x 17.50 = 17.50

6842.50 ÷ 17.50 = 391

So our equation is 6842.50 ÷ 17.50, and our solution is 391 tickets

Topic: Proportions

6 0

2 years ago