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3 years ago

If the population standard deviation is 10 , how large a sample is necessary to have a standard error that is

1 answer:

5 0

The standard error given a population standard deviation of $\sigma$ is $\dfrac\sigma{\sqrt n}$ . So if the desired standard error is $s$ , then

$s=\dfrac\sigma{\sqrt n}\implies \sqrt n=\dfrac\sigma s\imlies n=\dfrac{\sigma^2}{s^2}$

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A 34-foot pole casts a 30-foot shadow. At the same time, a nearby tree casts a 24-foot shadow. How tall is the tree?

artcher [175]

Answer:

27.2 ft

Step-by-step explanation:

Let's set up a ratio that represents the problem:

Object's Height (ft) : Shadow (ft)

Substitute with the dimensions of the 34 foot pole and its 30 foot shadow.

34 : 30

Find the unit rate:

The unit rate is when one number in a ratio is 1.

Let's make the Shadow equal to one by dividing by 30 on both sides.

Object's Height (ft) : Shadow (ft)

34 : 30

/30 /30

1.13 : 1

Now, let's multiply by 24 on both sides to find the height of the tree.

Multiply:

Object's Height (ft) : Shadow (ft)

1.13 : 1

x24 x24

27.2 : 24

Therefore, the tree is 27.2 feet tall.

7 0

3 years ago

PLEASE HELP!!!!

saveliy_v [14]

Answer:

Hi there!

Your answers are:

1) 38^10

2) 20^3

Step-by-step explanation:

1) Theres a property that goes like this:

(x^m)^n = x^mn

When you do a power of a power, you multiply them together!

2) There's a property that looks like this:

x^ m / x^n = x^ m-n

When dividing exponents, subtract!

Hope this helps!

8 0

3 years ago

There is a hot market at school for used graduation gowns, in fact the price is growing exponentially! Last week I could have go

Daniel [21]

Answer:

$100

Step-by-step explanation:

the equation to solve this is:

$y=12.5x+25$

$y=12.5x+25\\ =(12.5*6)+25\\ =75+25\\ =100$

(Assuming, of course, that this is a homework assignment and not you actually buying it cuz' in real life the numbers would be different from month to month)

4 0

3 years ago

4. (07.04 MC)

timofeeve [1]

Answer:

11779 ft

Step-by-step explanation:

We are given that

$\theta=23^{\circ}$

Distance between tower and plane,d=5000 ft

We have to find the distance between the plane and bird.

Let x be the distance between bird and plane

We know that

$tan\theta=\frac{perpendicular\;side}{Base}$

Using the formula

$tan23=\frac{5000}{x}$

$x=\frac{5000}{tan23}=11779.3 \approx 11779ft$

Hence, the distance between the plane and bird=11779 ft

6 0

3 years ago

An experiment is performed where a 6-sided die is rolled and then a 3-color spinner is spun. The possible outcomes for each even

Galina-37 [17]

It should be noted that the sample space for the experiment is {1R, 1B, 1Y, 2R, 2B, 2Y, 3R, 3B, 3Y, 4R, 4B. 4Y. 5R, 5B, 5Y, 6R, 6B, 6Y}

<h3>What is a sample space?</h3>

A sample space is a set of potential results from a random experiment. The letter "S" is used to denote the sample space. Events are the subset of possible experiment results. Depending on the experiment, a sample area may contain a variety of outcomes.

Total number of outcomes in this experiment = 6 × 3 = 18

Hence, the sample space will be:

{1R, 1B, 1Y, 2R, 2B, 2Y, 3R, 3B, 3Y, 4R, 4B. 4Y. 5R, 5B, 5Y, 6R, 6B, 6Y}

Learn more about sample space on:

brainly.com/question/10558496

#SPJ1

4 0

1 year ago