You are enrolling swimmers in a study on lung capacity. You want 25% of your sample to be those who compete at 100m or less distances and 50% to be swimmers who compete at 100m-500m distances and 25% to be swimmers who compete at >500m distances. You begin enrolling for your study at 5am at the pool. By 9 AM you have all of your 100-500m swimmers enrolled, and all of your >500m swimmers enrolled. This is an example of what type of sampling method

Answers

Answer 1

Answer:

Stratified sampling

Step-by-step explanation:

Samples may be classified as:

Convenient: Sample drawn from a conveniently available pool.

Random: Basically, put all the options into a hat and drawn some of them.

Systematic: Every kth element is taken. For example, you want to survey something on the street, you interview every 5th person, for example.

Cluster: Divides population into groups, called clusters, and each element in the cluster is surveyed.

Stratified: Also divides the population into groups. However, then only some elements of the group are surveyed.

In this question:

People divided by groups, for each group(<100, >100<500, >500), a number(not all) is selected, so stratified sampling.


Related Questions

Points T, R, and P, define _____Points B, A, and E are:

Point A is located at (2, 4). Point B is located at (-2, 4). Point C is located at (-2, -4). Point D is located at (2, -4). Point E is located at (4, 4).

Answers

Answer:

Point T,R,P not seen how I don't understand your question.

Teresita wanted to buy a dress for $50, but she decided to wait because she didn't have
enough money. A week later, the price had gone up 20%. Now she definitely had to wait to
buy it. A week later, she went back to the store, and the price had gone down 20% from the
last price. Teresita finally bought the dress. What did she pay for it?

Answers

Answer:

$48

Explanation:

> 50 x .20 = $10

$50 + $10= $60

-----------------------------

> 60 x .20 = $12

$60 - $12= $48

Which graph shows the quadratic function y = 3x2 + 12x + 10? (5 points)

The following graph is labeled A: A four quadrant graph with a parabola opening up, passing through the points negative 3, 1, negative 2, negative 2, and negative 1, 1 with the vertex at 2, negative 2. The following graph is labeled B: A four quadrant graph with a parabola opening up, passing through the points 1, 4, 2, 1, and 3, 4 with the vertex at 2, 1. The following graph is labeled C: A four quadrant graph with a parabola opening up, passing through the points negative 3, 5, negative 2, 2, and negative 1, 5 with the vertex at negative 2, 2. The following graph is labeled D: A four quadrant graph with a parabola opening up, passing through the points 1, 1, 2, negative 2, and 3, 1 with the vertex at 2, negative 2.

Answers

Answer:

The correct graph is A.

Answer:

A i got it right

Step-by-step explanation:

Solve for x.

5x - 3 = 12

A) X = 3
B) X = -3
C) X = -9/5
D) X = 9/5

Answers

Answer:

A. x = 3

Step-by-step explanation:

5x - 3 = 12

5x = 12 + 3

5x = 15

x = 15/5

= 3

Can someone help me solve this and explain how to solve if possible please?

Answers

The length of road is the range and the time
in days is the domain. Any measure of time, like years, days, minutes will always be the independent variable, D. What does it mean by set of values?


I need help answering this ASAP

Answers

Answer:

A the input x=3 goes to two different output values

Step-by-step explanation:

This is not a function

x = 3 goes to two different y values

x = 3 goes to t = 10 and y = 5

Assume that human body temperatures are normally distributed with a mean of 98.19 and a standard deviation of 0.61

Answers

Answer:

Ok I'm assuming that know what??

Step-by-step explanation:

PPPPPLLLLZZZZ HELPPPP
Use the function f(x) = -16x² + 60x + 16 to answer the questions.
Part A: Completely factor f(x). (2 points)
Part B: What are the x-intercepts of the graph of f(x)? Show your work. (2 points
Part C: Describe the end behavior of the graph of f(x). Explain. (2 points)
Part D: What are the steps you would use to graph f(x)? Justify that you can use the answers obtained in Part B and Part C to draw the graph

Answers

Here we have the quadratic function:

f(x) = -16*x^2 + 60*x + 16

We can see that it is in standard form:

y = a*x^2 + b*x + c

a) First we want to completely factorize the function f(x).

To do it, we first need to find the roots of f(x).

Remember that for a generic quadratic equation:

a*x^2 + b*x + c = 0

whit roots x₁ and x₂, the factorized form is:

a*(x - x₁)*(x - x₂)

And the roots are given by:

[tex]x = \frac{-b \pm \sqrt{b^2 - 4*a*c} }{2*a}[/tex]

Then for the case of f(x) = -16*x^2 + 60*x + 16, the roots are:

[tex]x = \frac{-60 \pm \sqrt{60^2 - 4*(-16)*16} }{2*(-16)} = \frac{-60 \pm 68}{-32}[/tex]

So the two roots are:

x₁ = (-60 + 68)/-32 = -0.25

x₂ = (-60 - 68)/-32 = 4

Then the factorized form is:

f(x) = -16*(x - 4)*(x + 0.25)

B) We already found the roots, which are:

x₁ =  -0.25

x₂ =  4

These are the x-intercepts:

(-0.25, 0) and (4, 0)

C) We can see that the leading coefficient is negative.

This means that the arms of the graph go downwards, so as |x| increases, the value of f(x) tends to negative infinity.

D) To graph f(x) we can find some of the points of the graph (like the x-intercepts and some more of them) and then connect them with a parabola curve, the graph that you will get is the one that you can see below.

If you want to learn more about this topic, you can read:

https://brainly.com/question/22761001

helppppp plsss ??? plssss ??

Answers

Answer:

3 is correct dear

i hope it will help u

Suppose a young sedentary woman wanted to lose 30 pounds of body fat in a period of 20 weeks. She now weighs 160 pounds and her activity level is such so she needs 15 Calories per pound of body weight to maintain her weight. Calculate the number of Calories she may consume daily in order to lose the 30 pounds by diet only. 1,000 1,250 1,400 1,650 1,900

Answers

Answer:

The answer is "1900"

Step-by-step explanation:

It takes 500 fewer calories per day for her to lose 1 lb of weight every week.

[tex]\to (15 \times 160)-500 =(2400)-500 =2400-500=1900[/tex]

What is the value of |-6|—|6|-(-6)?

The solution is

Answers

Answer:

6

Step-by-step explanation:

|-6| = 6

|6| = 6

- -6 = +6

so, we have

6 - 6 + 6 = 6

HELP ASAP PIC IS BELOW!!!

Answers

Answer:

55°

Step-by-step explanation:

Vertical angles are similar

Answered by GAUTHMATH

If the product of a and cis negative, you subtract the factors of the product to arrive at c. True False​

Answers

9514 1404 393

Answer:

  false

Step-by-step explanation:

The statement is nonsense (false). Regardless of the sign of a product, subtraction plays no part in anything related to it.

RATE OF CHANGE:
At the bakery shop, each baker works at his or her own speed, making the same
number of cakes each day. Marissa makes 28 cakes in 2 weeks, Carlos makes 60
cakes in 20 days, and Shelby makes 5 cakes in 2 days.
When the shop owner graphs the relationship between the number of cakes
made and days, who has the steepest graph? Explain.

Answers

Answer:

Carlos

Step-by-step explanation:

Hope this helps

Find the product and simplify your answer 6w(5w^2-5w+5)

Answers

Answer:

30w^3 - 30w^2 + 30w

Step-by-step explanation:

Basically multiply 6w by the numbers inside the parentheses

I NEED HELP ON C,E,F,G PLEASE ASAP!!!!

Answers

Answer:
C. 364.4
E. 14
F. 21
G. 96°

Which table represents a linear function

Answers

Answer:

3rd option (top right)

Step-by-step explanation:

3rd option represents a linear equation

y = -2x-1

Answered by GAUTHMATH

Problem 2 find m<GEF​

Answers

Answer:

m<GEF = 66°

Step-by-step explanation:

(72+60)/2

= 132/2

= 66

Answered by GAUTHMATH

Use the distributive property to find the product of the rational number.
5/2 (- 8/5 + 7/5)

Answers

9514 1404 393

Answer:

  -1/2

Step-by-step explanation:

The factor outside parentheses multiplies each term inside.

  5/2(-8/5 +7/5)

  = (5/2)(-8/5) +(5/2)(7/5)

  = -8/2 +7/2 = -1/2

help. WORTH 15 POINTS!!!

Answers

Answer:

x=27

Step-by-step explanation:

The sum of the angles of a triangle are 180 degrees

90 + x+15 + 2x-6 = 180

Combine like terms

3x+99=180

Subtract 99 from each side

3x+99-99=180-99

3x =81

Divide each side by 3

3x/3 = 81/3

x=27

CAN SOMEBODY ANSWER MY QUESTIONS !!!!​

Answers

9514 1404 393

Answer:

A''(-1, 2)B''(3, 5)C''(4, 3)

Step-by-step explanation:

Reflection over the line x=a is the transformation ...

  (x, y) ⇒ (2a -x, y)

Then the double reflection over x=a and x=b is the transformation ...

  (x, y) ⇒ (2b -(2a -x), y) = (2(b-a) +x, y)

That is, the result is translation by twice the distance between the lines. For a=1 and b=3, the transformation is ...

  (x, y) ⇒ (x +4, y) . . . . . . . translation to the right by 4 units.

  A(-5, 2) ⇒ A''(-1, 2)

  B(-1, 5) ⇒ B''(3, 5)

  C(0, 3) ⇒ C''(4, 3)

question is in picture

Answers

Answer: A

Step-by-step explanation:

(tangent is opposite over adjacent)

[tex]tan(40)=\frac{x}{3.8}\\x=3.8*tan(40)[/tex]

Flying against the wind, an airplane travels 3360 kilometers in hours. Flying with the wind, the same plane travels 7560 kilometers in 9 hours. What is the rate of the plane in still air and what is the rate of the wind?

Answers

Answer:

606.6 and 233.3 respectively

Step-by-step explanation:

Let the speed of plane in still air be x and the speed of wind be y.

ATQ, (x+y)*9=7560 and (x-y)*9=3360. Solving it, we get x=606.6 and y=233.3

Given coordinates A(3,3),B(2,5),C(4,3) complete transformation. Complete double reflection over the lines y=2 followed by y=0.​

Answers

9514 1404 393

Answer:

A"(3, -1)B"(2, 1)C"(4, -1)

Step-by-step explanation:

Reflection over 'a' then over 'b' will result in a translation of 2(b -a). Here, we have a=2, b=0, so the translation is 2(0-2) = -4. The reflection is over horizontal lines, so the transformation is ...

  (x, y) ⇒ (x, y -4)

  A(3, 3) ⇒ A"(3, -1)

  B(2, 5) ⇒ B"(2, 1)

  C(4,3) ⇒ C"(4, -1)

A study was conducted to determine if there was a difference in the driving ability of students from West University and East University by sending a survey to a sample of 100 students at both universities. Of the 100 sampled from West University, 15 reported they were involved in a car accident within the past year. Of the 100 randomly sampled students from East University, 12 students reported they were involved in a car accident within the past year. True or False. The difference in driving abilities at the two universities is statistically significant at the .05 significance level.

Answers

Answer:

False

Step-by-step explanation:

Before testing the hypothesis, we need to understand the central limit theorem and subtraction of normal variables.

Central Limit Theorem

The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]

Subtraction between normal variables:

When two normal variables are subtracted, the mean is the difference of the means, while the standard deviation is the square root of the sum of the variances.

West University:

15 out of 100, so:

[tex]p_W = \frac{15}{100} = 0.15[/tex]

[tex]s_W = \sqrt{\frac{0.15*0.85}{100}} = 0.0357[/tex]

East University:

12 out of 100, so:

[tex]p_E = \frac{12}{100} = 0.12[/tex]

[tex]s_E = \sqrt{\frac{0.12*0.88}{100}} = 0.0325[/tex]

Test the difference in driving abilities at the two universities:

At the null hypothesis we test if there is no difference, that is, the subtraction of the proportions is 0, so:

[tex]H_0: p_W - p_E = 0[/tex]

At the alternative hypothesis, we test if there is a difference, that is, if the subtraction of the proportions is different of 0. So

[tex]H_1: p_W - p_E \neq 0[/tex]

The test statistic is:

[tex]z = \frac{X - \mu}{s}[/tex]

In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, and s is the standard error.

0 is tested at the null hypothesis:

This means that [tex]\mu = 0[/tex]

From the two samples:

[tex]X = p_W - p_E = 0.15 - 0.12 = 0.03[/tex]

[tex]s = \sqrt{s_W^2+s_E^2} = \sqrt{0.0357^2+0.0325^2} = 0.0483[/tex]

Value of the test statistic:

[tex]z = \frac{X - \mu}{s}[/tex]

[tex]z = \frac{0.03 - 0}{0.0483}[/tex]

[tex]z = 0.62[/tex]

P-value of the test and decision:

The p-value of the test is the probability that the proportions differ by at least 0.03, which is P(|z| > 0.62), that is, 2 multiplied by the p-value of z = -0.62.

Looking at the z-table, z = -0.62 has a p-value of 0.2676.

2*0.2676 = 0.5352.

The p-value of the test is 0.5352 > 0.05, which means that the difference in driving is not statistically significant at the .05 significance level, and thus the answer is False.

Find x. Round your answer to the nearest tenth of a degree.

Answers

Answer: x=52.6°

Step-by-step explanation:

To find the value of x, we have to use our SOHCAHTOA. We can eliminate sine and cosine because both uses hypotenuse, which is not labelled. Therefore, we use tangent.

[tex]tan(x)=\frac{17}{13}[/tex]

To find x, we want to use inverse tangent.

[tex]x=tan^{-1}(\frac{17}{13} )[/tex]      [plug into calculator]

[tex]x=52.6[/tex]

Now, we know that x=52.6°.

Choose the correct elements in the set for the following:


{y | y is an integer and y >/= -3}


{3, 4, 5, 6, . . .}

{−2, −1, 0, 2, . . .}

{−1, 0, 1, 2, . . }

{−3, −2, −1, 0, . . .}


****PLEASE explain your answer****

Answers

Answer:

D

Step-by-step explanation:

Y => - 3 that is {−3, −2, −1, 0, . . .}

prove that.

lim Vx (Vx+ 1 - Vx) = 1/2 X>00 ​

Answers

Answer:

The idea is to transform the expression by multiplying [tex](\sqrt{x + 1} - \sqrt{x})[/tex] with its conjugate, [tex](\sqrt{x + 1} + \sqrt{x})[/tex].

Step-by-step explanation:

For any real number [tex]a[/tex] and [tex]b[/tex], [tex](a + b)\, (a - b) = a^{2} - b^{2}[/tex].

The factor [tex](\sqrt{x + 1} - \sqrt{x})[/tex] is irrational. However, when multiplied with its square root conjugate [tex](\sqrt{x + 1} + \sqrt{x})[/tex], the product would become rational:

[tex]\begin{aligned} & (\sqrt{x + 1} - \sqrt{x}) \, (\sqrt{x + 1} + \sqrt{x}) \\ &= (\sqrt{x + 1})^{2} -(\sqrt{x})^{2} \\ &= (x + 1) - (x) = 1\end{aligned}[/tex].

The idea is to multiply [tex]\sqrt{x}\, (\sqrt{x + 1} - \sqrt{x})[/tex] by [tex]\displaystyle \frac{\sqrt{x + 1} + \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}}[/tex] so as to make it easier to take the limit.

Since [tex]\displaystyle \frac{\sqrt{x + 1} + \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}} = 1[/tex], multiplying the expression by this fraction would not change the value of the original expression.

[tex]\begin{aligned} & \lim\limits_{x \to \infty} \sqrt{x} \, (\sqrt{x + 1} - \sqrt{x}) \\ &= \lim\limits_{x \to \infty} \left[\sqrt{x} \, (\sqrt{x + 1} - \sqrt{x})\cdot \frac{\sqrt{x + 1} + \sqrt{x}}{\sqrt{x + 1} + \sqrt{x}}\right] \\ &= \lim\limits_{x \to \infty} \frac{\sqrt{x}\, ((x + 1) - x)}{\sqrt{x + 1} + \sqrt{x}} \\ &= \lim\limits_{x \to \infty} \frac{\sqrt{x}}{\sqrt{x + 1}+ \sqrt{x}}\end{aligned}[/tex].

The order of [tex]x[/tex] in both the numerator and the denominator are now both [tex](1/2)[/tex]. Hence, dividing both the numerator and the denominator by [tex]x^{(1/2)}[/tex] (same as [tex]\sqrt{x}[/tex]) would ensure that all but the constant terms would approach [tex]0[/tex] under this limit:

[tex]\begin{aligned} & \lim\limits_{x \to \infty} \sqrt{x} \, (\sqrt{x + 1} - \sqrt{x}) \\ &= \cdots\\ &= \lim\limits_{x \to \infty} \frac{\sqrt{x}}{\sqrt{x + 1}+ \sqrt{x}} \\ &= \lim\limits_{x \to \infty} \frac{\sqrt{x} / \sqrt{x}}{(\sqrt{x + 1} / \sqrt{x}) + (\sqrt{x} / \sqrt{x})} \\ &= \lim\limits_{x \to \infty}\frac{1}{\sqrt{(x / x) + (1 / x)} + 1} \\ &= \lim\limits_{x \to \infty} \frac{1}{\sqrt{1 + (1/x)} + 1}\end{aligned}[/tex].

By continuity:

[tex]\begin{aligned} & \lim\limits_{x \to \infty} \sqrt{x} \, (\sqrt{x + 1} - \sqrt{x}) \\ &= \cdots\\ &= \lim\limits_{x \to \infty} \frac{\sqrt{x}}{\sqrt{x + 1}+ \sqrt{x}} \\ &= \cdots \\ &= \lim\limits_{x \to \infty} \frac{1}{\sqrt{1 + (1/x)} + 1} \\ &= \frac{1}{\sqrt{1 + \lim\limits_{x \to \infty}(1/x)} + 1} \\ &= \frac{1}{1 + 1} \\ &= \frac{1}{2}\end{aligned}[/tex].

Answer:

Hello,

Step-by-step explanation:

[tex]\displaystyle \lim_{x \to \infty} \sqrt{x}*(\sqrt{x+1}-\sqrt{x} ) \\\\\\= \lim_{x \to \infty}\dfrac{ \sqrt{x}*(\sqrt{x+1}-\sqrt{x} )*(\sqrt{x+1}+\sqrt{x} )}{\sqrt{x+1} +\sqrt{x} } \\\\= \lim_{x \to \infty} \dfrac{\sqrt{x} *1}{\sqrt{x+1} +\sqrt{x} } \\\\\\= \lim_{x \to \infty} \dfrac{1} {\sqrt {\dfrac {x+1} {x} }+\sqrt{\dfrac{x}{x} } } \\\\\\=\dfrac{1} {\sqrt {1}+\sqrt{1} } \\\\\\=\dfrac{1} {2} \\[/tex]

Move the numbers to the lines to order them from least to greatest.
least
greatest
67.98
68.6
68.11
Please answer ASAP

Answers

Answer:

67.98,68.11, 68.6

Find the remainder when f(x)=x3−4x2−6x−3 f ( x ) = x 3 − 4 x 2 − 6 x − 3 is divided by x+1

Answers

Answer:

The remainder is -2.

Step-by-step explanation:

According to the Polynomial Remainder Theorem, if we divide a polynomial P(x) by a binomial (x - a), then the remainder of the operation will be given by P(a).

Our polynomial is:

[tex]P(x) = x^3-4x^2-6x-3[/tex]

And we want to find the remainder when it's divided by the binomial:

[tex]x+1[/tex]

We can rewrite our divisor as (x - (-1)). Hence, a = -1.

Then by the PRT, the remainder will be:

[tex]\displaystyle\begin{aligned} R &= P(-1)\\ &=(-1)^3-4(-1)^2-6(-1)-3 \\ &= (-1)-4(1)+(6)-3 \\ &= -2 \end{aligned}[/tex]

The remainder is -2.

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Read the following excerpt from a media response essayThe ad features a brightly colored banner and a couple of twenty-somethings sitting comfortably together,smiling happily, and sharing a set of headphones to listen to music. Certainly the ad will catch the attention ofand appeal to young adults.In this excerpt, the writer isA.providing a thesis that reflects topic and viewpoint.B.ending the essay with a strong conclusionC.analyzing the advertising methods of the ad.D.giving an explanation of the target audience. Mark bought seeds, 5 packets of carrot seeds, 2 packets ofbean seeds, and 3 packets of pea seeds. If he randomlyselects 4 packets to plant, what is the probability that heselects 2 packets of carrots, 1 packet of beans, and 1 packetof peas? If Bromine has a charge of 1-, how many electrons does it have? write the equation of the graph, y=? SOMEBODY PLEASE HELP Select the correct answer.Which inequality represents all the solutions of 10(3x + 2) > 7(2x 4)?A. x > -4B. x < -4C. x > -3D. x < -3 please give me correct answer IM GIVING BRAINLESIT AND ANYTHING UNDER 20$ ON ANY APPROPIATE CURRENCY IF YOU ANSWER ALL OF THIS (PLEASE LABEL WHAT YOUR ANSWERING) How do Java scripts work?!I need the answer fast because My school homework is due tommorow! Imagine you do a test cross between a purple-flowered pea plant having serrated leaves (a dominant trait) and a white-flowered pea plant having smooth edges. If the purple-flowered plant is heterozygous for both traits, the expected ratio in the offspring is 1 purple-serrated:1 purple-smooth:1 white-serrated:1 white-smooth. Instead, you see 4 purple-serrated:1 purple-smooth:1 white-serrated:4 white-smooth. What is the explanation of this ratio Imagine you found S. aureus to be resistant to Penicillin by Kirby Bauer analysis, but susceptible to Penicillin treatment in liquid culture (in other words, a MIC was determined). Which of the following are possible explanations for this inconsistency?a. The concentration of Penicillin was higher in the Penicillin antibiotic disk than that used in liquid culture treatment. b. The Penicillin disks used for Kirby Bauer analysis were expired/no longer active. c. The concentration of bacteria was lower on the Mueller Hinton plate for Kirby Bauer analysis than that used in liquid culture treatment write the electronic configuration of the first 20 element explain Distribution and also explain the channel of Distribution the boys (like/learn) how to swim next year WHAT IS ONE OF THE MOST IMPORTANT FUNCTIONS OF ANY LEGAL SYSTEM? Trish's punch recipe calls for 8 liters of lemon-lime soda and 4 liters of cranberry juice, Jenny's punch recipe requires 7liters of lemon-lime soda and 6 liters of cranberry juice. Which recipe has a higher ratio of lemon-lime soda to cranberryjuice?( A, neither, the ratios are equivalentB. Trish's recipec. Jenny's recipeD. not enough information Given the following array definition, write a constant declaration named ArraySize that automatically calculates the size in bytes, of the array: newArray DWORD 10,20,30,40,50a) arraysize=(S-newArray) b) arraysize#(S-new,Array)/2 c) arraySize- (S-newArray)/4 d) arraySize- (S-arraySize) Based on a predicted level of production and sales of 20,000 units, a company anticipates total variable costs of $96,000, fixed costs of $24,000, and operating income of $163,200. Based on this information, the budgeted amount of contribution margin for 17,000 units would be: One-third of a number when subtracted from double of itself is equal to 10. Find the number.2xx3=10X=? need some help with this :) (11011+1001) base 2please slove this