Donald and Sara are surveying their neighbors about the community playground. Their questions, written on the survey, are below:

Donald: How many times do you visit the playground in a month?
Sara: Did you visit the playground this month?

Who wrote a statistical question and why?

Sara, because there will be variability in the responses collected
Donald, because every neighbor can give a different answer
Sara, because there can be only one answer to the question
Donald, because every neighbor will give the same answer

Answer:

120 ways

..................

Answer:

24

Step-by-step explanation:

4  friends

1st seat: 4 different people could sit here

Now there are 3 friends left

2nd seat: 3 different people could sit here

Now there are 2 friends left

3rd seat: 2 different people could sit here

Now there are 1 friends left

4th seat: 1 different people could sit here

4*3*2*1

24 ways

The rate of change of R with time in the given equation is 0.004 ohm/s

Given parameters:

[tex]\frac{1}{R} = \frac{1}{R_1} + \frac{1}{R_2} \\\\\frac{dR_1}{dt} = 0.3 \ ohm/s\\\\\frac{dR_2}{dt} = 0.2 \ ohm/s\\\\R_1 = 60 \ ohms\\\\R_2 = 80 \ ohms[/tex]

To find:

First determine the value of R from the given equation;

[tex]\frac{1}{R} = \frac{1}{R_1} + \frac{1}{R_2} \\\\\frac{1}{R} = \frac{1}{60} + \frac{1}{80} \\\\\frac{1}{R} = \frac{4 + 3}{240} \\\\\frac{1}{R} = \frac{7}{240} \\\\R = \frac{240}{7} = 34.286 \ ohms[/tex]

Finally, to determine the rate of change of R, differentiate the given equation.

[tex]\frac{-1}{R^2} \frac{dR}{dt} = \frac{-1}{R_1^2} \frac{dR_1}{dt} - \frac{1}{R_2^2} \frac{dR_2}{dt} \\\\\frac{1}{R^2} \frac{dR}{dt} = \frac{1}{R_1^2} \frac{dR_1}{dt} + \frac{1}{R_2^2} \frac{dR_2}{dt}\\\\\frac{dR}{dt} = R^2(\frac{1}{R_1^2} \frac{dR_1}{dt} + \frac{1}{R_2^2} \frac{dR_2}{dt})[/tex]

[tex]\frac{dR}{dt} = 34.286(\frac{1}{(60)^2} \times 0.3 \ \ \ + \ \ \ \frac{1}{(80)^2} \times 0.2)\\\\\frac{dR}{dt} = 34.286(8.333 \times 10^{-5} \ \ \ + \ \ \ 3.125 \times 10^{-5})\\\\\frac{dR}{dt} = 34.286(11.458 \times 10^{-5})\\\\\frac{dR}{dt} = 0.00393\\\\\frac{dR}{dt} \approx 0.004 \ ohm/s[/tex]

Thus, from the given equation the rate of change of R with time is 0.004 ohm/s

Learn more here: https://brainly.com/question/14796851

Answer:

the verified answer is wrong.

Step-by-step explanation:

OP forgot to square R (34.286)

0.1449 = 14.49% probability that 6 students or more will score an "A" on the final exam.

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

For each student, there are only two possible outcomes. Either they score an A, or they do not. The probability of a student scoring an A is independent of any other student, which means that the binomial probability distribution is used to solve this question.

Additionally, to find the proportion of students who scored an A, the normal distribution is used.

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

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

In which  is the number of different combinations of x objects from a set of n elements, given by the following formula.

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

And p is the probability of a success.

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

Normal Probability Distribution

Problems of normal distributions can be solved using the z-score formula.

In a set with mean and standard deviation , the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

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 p-value, we get the probability that the value of the measure is greater than X.

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

Proportion of students that scored an A:

Scores have a mean of 79 and a standard deviation of 11.3, which means that [tex]\mu = 79, \sigma = 11.3[/tex]

Scores of 90 or higher are graded an A, which means that the proportion is 1 subtracted by the p-value of Z when X = 90, so:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{90 - 79}{11.3}[/tex]

[tex]Z = 0.97[/tex]

[tex]Z = 0.97[/tex] has a p-value of 0.8340.

1 - 0.8340 = 0.166

The proportion of students that scored an A is 0.166.

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

Probability that 6 students or more will score an "A" on the final exam:

Binomial distribution.

22 students, which means that [tex]n = 22[/tex]

The proportion of students that scored an A is 0.166, which means that [tex]p = 0.166[/tex]

The probability is:

[tex]P(X \geq 6) = 1 - P(X < 6)[/tex]

In which

[tex]P(X < 6) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4) + P(X = 5)[/tex]

Then

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 0) = C_{22,0}.(0.166)^{0}.(0.834)^{22} = 0.0184[/tex]

[tex]P(X = 1) = C_{22,1}.(0.166)^{1}.(0.834)^{21} = 0.0807[/tex]

[tex]P(X = 2) = C_{22,2}.(0.166)^{2}.(0.834)^{20} = 0.1687[/tex]

[tex]P(X = 3) = C_{22,3}.(0.166)^{3}.(0.834)^{19} = 0.2239[/tex]

[tex]P(X = 4) = C_{22,4}.(0.166)^{4}.(0.834)^{18} = 0.2117[/tex]

[tex]P(X = 5) = C_{22,5}.(0.166)^{5}.(0.834)^{17} = 0.1517[/tex]

Then

[tex]P(X < 6) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4) + P(X = 5) = 0.0184 + 0.0807 + 0.1687 + 0.2239 + 0.2117 + 0.1517 = 0.8551[/tex]

[tex]P(X \geq 6) = 1 - P(X < 6) = 1 - 0.8551 = 0.1449[/tex]

Thus

0.1449 = 14.49% probability that 6 students or more will score an "A" on the final exam.

For a problem that used the normal distribution, you can check https://brainly.com/question/15181104, and for a problem that used the binomial distribution, you can check https://brainly.com/question/15557838

Answer:

0.85714285714286 x 100 = 85.7143%.

Step-by-step explanation:

Answer:

27.756

Step-by-step explanation:

1) Move all the decimal points to the right and do the multiplication

  18 * 1524 = 27756

1.8 to 19 = one move

15.42 to 1542 = two moves

total three decimal point shifts

2) count the number (total) that you moved the decimal points

3) starting from the right move the decimal point that many times to the LEFT in for the answer

27.756

Answer:

solution (-2, 5/3  ).

Step-by-step explanation:

Given : y =  + 3  and x = –2.

To find : What is the solution to the system of equations.

Solution : We have given that y = + 3 ------equation (1)

and                                            x = –2.   ------equation (2)

On plugging the x = -2 in equation (1)

y =  + 3

y =  + 3 .

On simplification we get ,

y = .

Therefore, solution (-2, 5/3 ).

Answer:

15 years

Step-by-step explanation:

Given the quadratic regression model:

y = 8x² - 40x+6 ; where

y = Number of people attending graduate school ;

x = number of years

The value of x when y = 1206

The equation becomes :

1206 = 8x² - 40x+6

1206 - 6 = 8x² - 40x

1200 = 8x² - 40x

Divide through by 8

150 = x² - 5x

x² - 5x - 150 = 0

x² - 15x + 10x - 150 = 0

x(x - 15) + 10(x - 15)

x - 15 = 0 or x + 10 = 0

x = 15 or x = - 10

Number of years can't be negative,

Hence, x = 15 years

9514 1404 393

Answer:

  (a)  C = 92/n

Step-by-step explanation:

The "inversely proportional" relation is represented by the equation ...

  C = k/n

The value of k can be found from the given values of C and n.

  23 = k/4

  23×4 = k = 92

Then the relationship is ...

  C = 92/n

Answer:

x = 74.74 m

Step-by-step explanation:

you need simple trigonometry to solve it

cosine of an angle is the ratio of the adjacent side to the hypotenuse

cos(42.2) is about 0.74

so X / Hypotenuse = 0.74

we know hypotenuse is 101 m

X / 101 = 0.74

x = 74.74 m

hope this helped!

Answer:

t=7.27 years

Step-by-step explanation:

Let the money be p and t will be the number of years that will be needed for the money to get double.

ATQ, 2p=p*(1+0.1)^t

2=(1.1)^t

log(2)/log(1.1)=t, t=7.27

The mass density in kg/m3 will be -  15 x [tex]10^{-2}[/tex] Kg/m3.

We have a 100.0 m long polymer cable of uniform circular cross section and of diameter 0.4cm has a mass of 1885.0 gm.

We have to determine its mass density in kg/m3.

The amount of mass per unit volume present in the body is called its mass density.

According to question, we have -

Length of polymer cable = 100.0 m

diameter of polymer cable = 0.4 cm = 0.004 m

Therefore, its radius = 0.002 m

The mass density of the wire will be -

[tex]\rho =\frac{m}{\pi r^{2} l}[/tex]

[tex]\rho[/tex] = [tex]\frac{1885}{3.14 \times0.002 \times 0.002 \times 100 }[/tex]

[tex]\rho = \frac{1885}{0.001256}[/tex] = 1500796.1 g/m3

1 Kg = 1000g

1g = 1/1000kg

1500796.1g = 1500.7 Kg = 15 x [tex]10^{-2}[/tex] Kg

Therefore, mass density = 15 x [tex]10^{-2}[/tex] Kg/m3

Hence, the mass density in kg/m3 will be -  15 x [tex]10^{-2}[/tex] Kg/m3.

To solve more questions on mass density, visit the link below -

https://brainly.com/question/4893600

#SPJ2

Answer: A (10)

Step-by-step explanation:

Plug in Q(-3) into formula x^2-x-2

(-3)^2-(-3)-2= 9+3-2

=10

Answer:

16

Step-by-step explanation:

Inverse variation is of the form

xy = k where k is a constant

x=4 and y = 32

4*32 = k

128 = k

xy = 128

Let x = 8

8y = 128

Divide each side by 8

8y/8 = 128/8

y =16

Answer:

The p-value of the test is 0.0007 < 0.01, which means that the class demonstrates that the percentage was higher in Owensboro, KY.

The possible proportion of patrons that do borrow books from the Owensboro Library is 0.82.

Step-by-step explanation:

For Americans using library services, the American Library Association claims that at most 67% of patrons borrow books. Test if the proportion is higher in Owensboro, KY.

At the null hypothesis, we test if the proportion is of at most 0.67, that is:

[tex]H_0: p \leq 0.67[/tex]

At the alternative hypothesis, we test if the proportion is of more than 0.67, that is:

[tex]H_1: p > 0.67[/tex]

The test statistic is:

[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, [tex]\sigma[/tex] is the standard deviation and n is the size of the sample.

0.67 is tested at the null hypothesis:

This means that [tex]\mu = 0.67, \sigma = \sqrt{0.67*0.33}[/tex]

The class randomly selected 100 patrons and found that 82 borrowed books.

This means that [tex]n = 100, X = \frac{82}{100} = 0.82[/tex]

Value of the test statistic:

[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

[tex]z = \frac{0.82 - 0.67}{\frac{\sqrt{0.67*0.33}}{\sqrt{100}}}[/tex]

[tex]z = 3.19[/tex]

P-value of the test and decision:

The p-value of the test is the probability of a finding a sample proportion of 0.82 or above, which is 1 subtracted by the p-value of z = 3.19.

Looking at the z-table, z = 3.19 has a p-value of 0.9993.

1 - 0.9993 = 0.0007

The p-value of the test is 0.0007 < 0.01, which means that the class demonstrates that the percentage was higher in Owensboro, KY.

What is the possible proportion of patrons that do borrow books from the Owensboro Library?

The sample proportion of 0.82.

Answer:

-39

Step-by-step explanation:

Answer:

I think its B. Y = -3x + 1

Step-by-step explanation:

Sorry if this is wrong.

Answer:

1

Step-by-step explanation:

First, find the inverse of the original function.

x = 2y + 2

x-2/2

Second, substitute x with 4 and solve.

4-2/2

2/2

1

Best of Luck!

If f(x) = 2x + 2 is invertible, then its inverse is another function f ⁻¹(x) such that

f(f ⁻¹(x)) = 2 f ⁻¹(x) + 2 = x

Solve for f ⁻¹(x) :

2 f ⁻¹(x) + 2 = x

2 f ⁻¹(x) = x - 2

f ⁻¹(x) = (x - 2)/2 = x/2 - 1

Then when x = 4, we have f ⁻¹ (4) = 4/2 - 1 = 2 - 1 = 1.

Answer:

1/4

Step-by-step explanation:

Probability = 3/(5+3+4)

= 3/12 or 1/4

-105

Multiply first, then subtract, then add.

Answer: the answer would be -105.

Answer:

145

Step-by-step explanation:

Angles in a straight line = 180

So,

Let unkown angle be x,

x+35=180

x=180-35

x=145

Answer:

Kindly check explanation

Step-by-step explanation:

H0 : μ = 15.7

H1 : μ < 15.7

This is a one sample t test :

Test statistic = (xbar - μ) ÷ (s/√(n))

n = sample size = 33

Using calculator :

The sample mean, xbar = 15.41

The sample standard deviation, s = 0.419

Test statistic = (15.41 - 15.70) ÷ (0.419/√(33))

Test statistic = - 3.976

Using the Pvalue calculator :

Degree of freedom, df = n - 1 ; 33 - 1 = 32

Pvalue(-3.976, 32) = 0.000187

Decison region :

Reject H0 if Pvalue < α

Since Pvalue < α ; we reject H0

There is significant evidence to conclude that the true average height of the seedlings treated with an extract from Vinca minor roots is less than 15.7 cm.

Answer:

i have attached pic of the graph

i hope this helps you

Answer:

6.2

Step-by-step explanation:

to fine the mean of numbers

1) add the given no.........3+5+6+7+9+6+8 which is 44

2)divide the result by the amount of the numbers....44/7

the answer will be 6.285.....

Answer:

Divide 79 by 8

Step-by-step explanation:

79/8

= 9.875