Is on in which every member of the population has an equal chance of being selected for the sample?

Explain how to find the area of an enlarged polygon if you know the area of the original polygon and the scale factor of the enl

julia-pushkina [17]

Yo just need to multiply area to that scale factor,

5 0

3 years ago

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There are two college entrance exams that are often taken by students, Exam A and Exam B. The composite score on Exam A is appro

elena55 [62]

Answer:

B.The score on Exam A is better, because the percentile for the Exam A score is higher.

Step-by-step explanation:

Problems of normally distributed samples can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this problem, we have that:

Two exams. The exam that you did score better is the one in which you had a higher zscore.

The composite score on Exam A is approximately normally distributed with mean 20.1 and standard deviation 5.1.

This means that $\mu = 20.1, \sigma = 5.1$ .

You scored 24 on Exam A. So

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{24 - 20.1}{5.1}$

$Z = 0.76$

The composite score on Exam B is approximately normally distributed with mean 1031 and standard deviation 215.

This means that $\mu = 1031, \sigma = 215$ .

You scored 1167 on Exam B, s:

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{1167 - 1031}{215}$

$Z = 0.632$

You had a better Z-score on exam A, so you did better on that exam.

The correct answer is:

B.The score on Exam A is better, because the percentile for the Exam A score is higher.

3 0

4 years ago

Joe is building a post for his mailbox. To find the correct dimensions, he needs to expand this expression: (x-3) (x-9) (x-4) Se

kolbaska11 [484]

Answer:

$(x-3)(x-9)(x-4)=x^3-16x^2+75x-108$

Step-by-step explanation:

Given:

The expression to expand is given as:

$(x-3)(x-9)(x-4)$

Let us expand the first two binomials of the given expression using FOIL method.

The FOIL method states that:

$(a + b)(c + d) = ac + ad + bc + bd$

$(x-3)(x-9)=(x\times x)+(x\times -9)+(-3\times x)+(-3\times -9)\\\\(x-3)(x-9)=x^2-9x-3x+27=x^2-12x+27$

Now, let us multiply the result with the remaining binomial. Multiplying each term of the trinomial with each term of the binomial, we get:

$(x^2-12x+27)(x-4)\\\\= (x^2\times x)+ (x^2\times -4)+(-12x\times x)+(-12x\times -4)+(27\times x)+(27\times -4)\\\\=x^3-4x^2-12x^2+48x+27x-108\\\\=x^3-16x^2+75x-108...........(\because-12x^2-4x^2=-16x^2,48x+27x=75x)$

Therefore, the equivalent expression after expanding is given as:

$(x-3)(x-9)(x-4)=x^3-16x^2+75x-108$

3 0

3 years ago

Y= -2 (x+2)^2-8<br>vertex=?<br>how to graph?

MissTica

Https://www.desmos.com/calculator you can use this calculator just plug the what y= in it and it will show you the graph and the vertex

7 0

3 years ago

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There are 80 dogs and cats in the animal shelter. The ratio of dogs to cats is 5/11. How many of the animals are dogs

Dima020 [189]

Answer:

25 dogs and 55 cats

Step-by-step explanation:

5/11 ratio, first add those up which you get 16

Then divide the total amount of animals by the ratio-80

80/16 = 5

(5*5)/(11*5)

25 dogs and 55 cats

4 0

3 years ago