After the first exam in a statistics course, the professor surveyed 14 randomly-selected students to determine the relation between the amount of time they spent studying for the exam and exam score. She found that a linear relation exists between the two variables. The least-squares regression line that describes this relation is: y​=6.3333x+53.0298.

Required:
a. Predict the exam score of a student who studies 2 hours.
b. Interpret the slope.
c. What is the mean score of students who did not study?
d. A student who studies 5 hours for the exam scored 81 on the exam. Is this student's exam score above or below average among all students who studies 5 hours?

Answers

Answer 1

Solution :

Given :

Equation :

y = 6.3333 x + 53.0298

Here, x = number of hours studied

         y = the exam score

a). To predict the exam score, we have to replace x in the least square regression line by 2 :

   y = 6.3333 x + 53.0298

   y = 6.3333 (2) + 53.0298

      = 65.6964

Thus he predicted exam score is 65.6964

b). The slope is the co-efficient of x in the least squares regression line :

  Slope = 6.3333

 The slope represents the average increase in y as x increases by 1.

  The exam score increases on average by 6.3333 points per hour studied.

c). The mean score of the [tex]\text{ students who did not study}[/tex] (studied 0 hours) is obtained by replacing x in the least squares regression line by 0 :

  y = 6.3333 x + 53.0298        

 y = 6.3333 (0) + 53.0298

    = 53.0298

d). To predict the exam score of a student who studied 5 hours, we replace x in the least squares regression line by 2 :

   y = 6.3333 x + 53.0298

   y = 6.3333 (5) + 53.0298

   y = 84.6963

Thus the average exam score of a student who studied 5 hours is 84.6963

Since the actual exam score 81 is less than the average exam score of 84.6963 the student's exam score is below the average.


Related Questions

Which inequality represents all numbers x on a number line that are farther from −8 than from −4?

Answers

Answer:

x - 8>-4-x

Step-by-step explanation:

Looking at x - 8>-4-x

Collect the like terms;

x+x > -4 + 8

2x < 4

x > 4/2

x < 2

Since the values of x are greater than 2,this shows that they are positive values and will be farther from -8 than -4

Pls help ASAP!!!!!!!!!!! I NEED HELP IMMEDIATELY!!!
Jaime had ten posters, but only five could fit on his closet door. How many different ways can he arrange the five posters out of the ten on his closet door?



A. 252
B. 648
C. 6,048
D. 30,240

Answers

Answer:

its c

Step-by-step explanation:

The answer to the question is 6,048

What’s the value of X????

Answers

Answer:
137

Step-by-step explanation:

Sum of opposite angles in a quadrilateral embedded in a circle=180

43+x=180

X=180-43

X=137

I was wondering if someone could answer this :)

Answers

Answer:

17

Step-by-step explanation:

2a+30 = 4a-4

+4 +4

2a+34 = 4a

-2a -2a

34 = 2a

÷2 ÷2

a=17

Hope this helps! :)

Answer:

A = 17

Step-by-step explanation:

Opposite angles are congruent in a parallelogram

Hence 2a + 30 = 4a - 4

( Note that we've just created an equation that we can use to solve for a)

We now solve for a

2a + 30 = 4a - 4

Add 4 to both sides

2a + 34 = 4a

Subtract 2a from both sides

34 = 2a

Divide both sides by 2

a = 17

Bill can hit a bucket of 323 golf balls in 17 hours.
How many golf balls can Bill hit in 23 hours?

Answers

Bill can hit 437 golf balls in 23 hours.

Explanation:

Bill’s unit rate of golf balls per hour is:
323 ÷ 17 = 19

19 golf balls per hour

To find how many golf balls Bill can hit in 23 hours, multiply:
19 • 23 = 437

Therefore, Bill can hit 437 golf balls in 23 hours.

Please, say if my answer is right
If its, glad to help!

-SpaceMarsh

0.0543 nearest whole number

Answers

0.0543 nearest whole number is 1 i think

Answer:

0

Step-by-step explanation:

Ignore the next 2 numbers after 0.05. To the nearest whole number, round 0.05 to the nearest tenth, 0.1. Then round that to the nearest whole number, 0, which is your answer.

PLEASE HELP ME I HAVE TO PASS THIS TEST

30 POINTS

Answers

Answer:

Hi, there the answer is

These are the equations with exactly one solution

-5x + 12 = –12x – 12

-5x + 12 = 5x + 12

-5x + 12 = 5x – 5

Hope This Helps :)

Step-by-step explanation:

First degree equations

A first degree equation has the form

ax + b = 0

There are some special cases where the equation can have one, infinitely many or no solution

If , the equation has exactly one solution

If a=0 and b=0 the equation has infinitely many solutions, because it doesn't matter the value of x, it will always be true that 0=0

If a=0 and  the equation has no solution, because it will be equivalent to b=0 and we are saying it's not true. No matter what x is, it's a false statement.

We have been given some equations, we only need to put them in standard form

-5x + 12 = –12x – 12

Rearranging

7x + 24 = 0

It has exactly one solution because a is not zero

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

-5x + 12 = 5x + 12

Rearranging

-10x + 0 = 0

It has exactly one solution because a is not zero

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

-5x + 12 = 5x – 5

Rearranging

-10x + 17 = 0

It has exactly one solution because a is not zero

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

-5x + 12 = -5x – 12

Rearranging

0x + 24 = 0

It has no solution, no matter what the value of x is, it's impossible that 24=0

Answer: These are the equations with exactly one solution

-5x + 12 = –12x – 12

-5x + 12 = 5x + 12

-5x + 12 = 5x – 5

Hi the answer is -5x+12=-12x-12

Which state ment is true regarding the graphed function
F(4)= g(4)
F(4)= g(-2)
F(2)= g(-2)
F(-2)= g(-2)

Answers

Answer:

F(-2)= g(-2)

Step-by-step explanation:

F(-2)= g(-2), both function have the same points of intersect.


[tex]4 \sqrt{(3x}^{3} [/tex]
write in exponential form​

Answers

Answer:

[tex]4(3x)^{\frac{3}{2} }[/tex]

Step-by-step explanation:

4(3x) 3/2
hope that helps

Find the value of X

Answers

Answer:

100°

Step-by-step explanation:

the lower right angle is 180-149 = 31°

the sum of all three angles in a triangle is 180°.

so the solution is 180-31-49

What is the common ratio for the geometric sequence below, written as a fraction?

768, 480, 300, 187.5, …


/

Answers

9514 1404 393

Answer:

  5/8

Step-by-step explanation:

Since the ratio is common, it can be found from the ratio of any pair of adjacent terms.

  r = 480/768 = (5·96)/(8·96) = 5/8

The common ratio is 5/8.

Solve for X in the triangle. Round your answer to the nearest tenth

Answers

Answer:

[tex]\displaystyle x \approx 9.9[/tex]

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to Right  

Equality Properties

Multiplication Property of Equality Division Property of Equality Addition Property of Equality Subtraction Property of Equality

Trigonometry

[Right Triangles Only] SOHCAHTOA[Right Triangles Only] sinθ = opposite over hypotenuse

Step-by-step explanation:

Step 1: Define

Identify variables

Angle θ = 64°

Opposite Leg = x

Hypotenuse = 11

Step 2: Solve for x

Substitute in variables [sine]:                                                                           [tex]\displaystyle sin(64^\circ) = \frac{x}{11}[/tex][Multiplication Property of Equality] Multiply 11 on both sides:                      [tex]\displaystyle 11sin(64^\circ) = x[/tex]Rewrite:                                                                                                             [tex]\displaystyle x = 11sin(64^\circ)[/tex]Evaluate:                                                                                                           [tex]\displaystyle x = 9.88673[/tex]Round:                                                                                                               [tex]\displaystyle x \approx 9.9[/tex]

simplify -5-√-44

i have no idea

Answers

Answer:

Undefined

Step-by-step explanation:

The square root of a negative number does not exist in the set of real numbers so it would be Undefined

Which equation shows the point-slope form of the line that passes through (3, 2) and has a slope of 1/3
O y + 2 =1/3(x + 3)
O y-2=1/3(x-3)
O y + 3 = 1/3(x+ 2)
O y-3= 1/3(x-2)

Answers

Answer:

y - 2 = 1/3(x - 3)

Step-by-step explanation:

Point slope form is y - y1 = m(x - x1), where m is the slope and (x1, y1) is a point on the line.

Plug in the slope:

y - y1 = m(x - x1)

y - y1 = 1/3(x - x1)

Plug in the given point:

y - y1 = 1/3(x - x1)

y - 2 = 1/3(x - 3)

So, the correct answer is y - 2 = 1/3(x - 3)

In △CDE, DE=14, CE=9, and m∠E=71∘. What is the length of CD⎯⎯⎯⎯⎯⎯? Enter your answer, rounded to the nearest hundredth, in the box.

Answers

Answer:

13.96units

Step-by-step explanation:

To get the length of CD, we will use the cosine rule as shown:

CD² = DE²+CE²-2(DE)(CE)cos m<E

Substitute the given values

CD² = 14²+9²-2(14)(9)cos71

CD² = 196 + 81 - 252cos71

CD² =277 - 252cos71

CD² = 277 - 82.0431

CD² = 194.95682

CD = √194.95682

CD = 13.96 units

Hence the length of CD of 13.96units

Which pair of expressions below are equivalent?

a. 7(2n) and 9
b. 3n + 5n and 15n
c. 4(2n-6) and 8n - 24
d. 7(2n) and 72n​

Answers

Answer:

The answer is C

Hope this helped!

What is the value of z in the equation 3z+9=z?

Answers

In the exact form, Z equals -9/2

Margot surveyed a random sample of 180 people from the United States about their favorite sports to watch. Then she sent separate, similar, survey to a random sample of 180 people from the United Kingdom. Here are the results:

Favorite sport to watch United States United kingdom Total
Basketball 60 51 111
Football 67 14 81
Soccer 28 86 114
Tennis 25 29 54
Total 180 180 360

Margot wants to perform a x^2 test of homogeneity on these results. What is the expected count for the cell corresponding to people from the United Kingdom whose favorite sports to watch is tennis?

Answers

Answer:

27

Step-by-step explanation:

The expected count in a χ² test can be obtained thus :

Expected count for each each point in a two way table ::

(row total * column total) / total

Therefore, expected count for cell corresponding to people from United Kingdom whose favorite sport is tennis :

Row total = (51+14+86+29) = 180

Column total = (25 + 29) = 54

Total = 360

Hence,

Expected count = (180 * 54) / 360

Expected count = 27

simplify the expression (2r^4y4xy^2) completely

Answers

Step-by-step explanation:

we can simplify the stuff inside the parentheses to

[tex] \frac{ {x}^{3} }{2y} [/tex]

now we need to multiply it with itself, giving us

[tex] \frac{ {x}^{6} }{4 {y}^{2} } [/tex]

so yeah, D is the correct answer

El primer día de la tormenta de nieve hubo 9,2 centímetros de nieve. Durante el segundo día de la tormenta, cayeron otros 18,2 centímetros. Si la nevada total durante la tormenta de nieve de tres días fue de 39,1 centímetros, ¿cuánta nieve cayó el tercer día?​

Answers

Answer:

11.7

Step-by-step explanation:

39.1 - 9.2 = 29.9

29.9 - 18.2 = 11.7

A technical machinist is asked to build a cubical steel tank that will hold of water. Calculate in meters the smallest possible inside length of the tank. Round your answer to the nearest .

Answers

Answer:

The smallest possible length is 0.83m

Step-by-step explanation:

Given

[tex]Volume = 565L[/tex]

Required

The smallest length of the tank

Since the tank is cubical, then the volume is:

[tex]Volume = Length^3[/tex]

This gives:

[tex]565L= Length^3[/tex]

Express as [tex]m^3[/tex]

[tex]\frac{565m^3}{1000} = Length^3[/tex]

[tex]0.565m^3 = Length^3[/tex]

Take cube roots of both sides

[tex]0.8267m = Length[/tex]

Rewrite as:

[tex]Length = 0.8267m[/tex]

Approximate

[tex]Length = 0.83m[/tex]

What is the area of the parallelogram shown?

Answers

Answer:

Area = 96 square m

Step-by-step explanation:

[tex]Area = base \times height = 12 \times 8 = 96 \ m^2[/tex]

Answer:

The area of parallelogram is 96 m ².

Step-by-step explanation:

According to the question , we have given a parallelogram with base 12 m and height is 8 m. We need to find the area of parallelogram.

Solution :-

Using Formula

Area of parallelogram = Base × Height

Substitute the values into this formula

Area of parallelogram = 12 m × 8 m

multiply, we get

Area of parallelogram = 96 m²

Therefore, The area of parallelogram is 96 m ².

HELPPPPOOOPPPPOPPPPPPPP

Answers

the answer is b. if you look at the line it intercepts with x at the point -8. and if you look at where it intercepts with y it’s at -2.

Answer:

Your answer would be B

Step-by-step explanation:

So right away you can get rid of a and d since they are positive numbers, there is no positive numbers in the graph were the line is.

So we know that the y-intercept is -2 (as you can see the line pass through (0,-2))

And we know the y intercept is -8 (since the line pass through (-8,0))

so you are left with b and c, c is incorrect because the -2 goes through the y-intercept not the x.

The right choice is b, it states that the x-intercept -8 pass through the line, the y-intercept is -2

Your welcome and hoped this helped!

which will result in a perfect square trimonial

Answers

Answer:

No choices listed.

Step-by-step explanation:

Prove the formula that:
((∃x)(F(x)∧S(x))→(∀y)(M(y)→W(y)))∧((∃y)(M(y)∧¬W(y)))
⇒(∀x)(F(x)→¬S(x))

Answers

Step-by-step explanation:

Given: [∀x(L(x) → A(x))] →

[∀x(L(x) ∧ ∃y(L(y) ∧ H(x, y)) → ∃y(A(y) ∧ H(x, y)))]

To prove, we shall follow a proof by contradiction. We shall include the negation of the conclusion for

arguments. Since with just premise, deriving the conclusion is not possible, we have chosen this proof

technique.

Consider ∀x(L(x) → A(x)) ∧ ¬[∀x(L(x) ∧ ∃y(L(y) ∧ H(x, y)) → ∃y(A(y) ∧ H(x, y)))]

We need to show that the above expression is unsatisfiable (False).

¬[∀x(L(x) ∧ ∃y(L(y) ∧ H(x, y)) → ∃y(A(y) ∧ H(x, y)))]

∃x¬((L(x) ∧ ∃y(L(y) ∧ H(x, y))) → ∃y(A(y) ∧ H(x, y)))

∃x((L(x) ∧ ∃y(L(y) ∧ H(x, y))) ∧ ¬(∃y(A(y) ∧ H(x, y))))

E.I with respect to x,

(L(a) ∧ ∃y(L(y) ∧ H(a, y))) ∧ ¬(∃y(A(y) ∧ H(a, y))), for some a

(L(a) ∧ ∃y(L(y) ∧ H(a, y))) ∧ (∀y(¬A(y) ∧ ¬H(a, y)))

E.I with respect to y,

(L(a) ∧ (L(b) ∧ H(a, b))) ∧ (∀y(¬A(y) ∧ ¬H(a, y))), for some b

U.I with respect to y,

(L(a) ∧ (L(b) ∧ H(a, b)) ∧ (¬A(b) ∧ ¬H(a, b))), for any b

Since P ∧ Q is P, drop L(a) from the above expression.

(L(b) ∧ H(a, b)) ∧ (¬A(b) ∧ ¬H(a, b))), for any b

Apply distribution

(L(b) ∧ H(a, b) ∧ ¬A(b)) ∨ (L(b) ∧ H(a, b) ∧ ¬H(a, b))

Note: P ∧ ¬P is false. P ∧ f alse is P. Therefore, the above expression is simplified to

(L(b) ∧ H(a, b) ∧ ¬A(b))

U.I of ∀x(L(x) → A(x)) gives L(b) → A(b). The contrapositive of this is ¬A(b) → ¬L(b). Replace

¬A(b) in the above expression with ¬L(b). Thus, we get,

(L(b) ∧ H(a, b) ∧ ¬L(b)), this is again false.

This shows that our assumption that the conclusion is false is wrong. Therefore, the conclusion follows

from the premise.

15

Use implicit differentiation to find an equation of the tangent line to the curve at the given point. y2(y2 − 4) = x2(x2 − 5) (0, −2) (devil's curve)

Answers

Answer:

Step-by-step explanation:

Given that:

[tex]y^2 (y^2-4) = x^2(x^2 -5)[/tex]

at point (0, -2)

[tex]\implies y^4 -4y^2 = x^4 -5x^2[/tex]

Taking the differential from the equation above with respect to x;

[tex]4y^3 \dfrac{dy}{dx}-8y \dfrac{dy}{dx}= 4x^3 -10x[/tex]

Collect like terms

[tex](4y^3 -8y)\dfrac{dy}{dx}= 4x^3 -10x[/tex]

[tex]\dfrac{dy}{dx}= \dfrac{4x^3 -10x}{4y^3-8y}[/tex]

Hence, the slope of the tangent line m can be said to be:

[tex]\dfrac{dy}{dx}= \dfrac{4x^3 -10x}{4y^3-8y}[/tex]

At point (0,-2)

[tex]\dfrac{dy}{dx}= \dfrac{4(0)^3 -10(0)}{4(-2)^3-8-(2)}[/tex]

[tex]\dfrac{dy}{dx}= \dfrac{0 -0}{4(-8)+16}[/tex]

[tex]\dfrac{dy}{dx}= 0[/tex]

m = 0

So, we now have the equation of the tangent line with slope m = 0 moving through the point (x, y) = (0, -2) to be:

(y - y₁ = m(x - x₁))

y + 2 = 0(x - 0)

y + 2 = 0

y = -2

NEED HELP ASAP PLEASE
Assume that a three-month CD purchased for $3000 pays simple interest at an annual rate of 10%. How much total interest does it earn?

$ ____

What is the balance at maturity? ______

Answers

Answers:

interest = $75balance at maturity = $3075

=============================================================

Explanation:

The simple interest formula is

i = p*r*t

where in this case,

p = 3000 = principal (amount deposited)r = 0.10 = annual interest rate in decimal formt = 3/12 = 0.25 = number of years

So,

i = p*r*t

i = 3000*0.10*0.25

i = 75 is the amount of interest earned

This adds onto the initial deposit to get the final balance when the CD matures (ie when you're able to withdraw the money without penalties)

The balance at maturity is p+i = 3000+75 = 3075 dollars

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

In short, you deposit $3000 into the CD and have to wait 3 months for the amount to update to $3075.

solve the system of equations y=x-7 y=x^2-9x+18

Answers

9514 1404 393

Answer:

  (x, y) = (5, -2)

Step-by-step explanation:

Equating expressions for y, we have ...

  x^2 -9x +18 = x -7

  x^2 -10x +25 = 0 . . . . . add 7-x to both sides

  (x -5)^2 = 0 . . . . . . . . factor

The value of x that makes the factor(s) zero is x=5. The corresponding value of y is ...

  y = x -7 = 5 -7 = -2

The solution is (x, y) = (5, -2).

X Y
-10 2
-15 3
-25 5

Determine whether y varies directly with x. If so, find the constant of variation and write the equation

Answers

Answer:

x = -5y

Step-by-step explanation:

x = ay

-10 = 2a

a = -5

x = ay

-15 = 3a

a = -5

x = ay

-25 = 5a

a = -5

HELP plsssss I will GIVE YOU BRAINLYEST

Answers

Answer: B

Step-by-step explanation:

Answer:

-5ºC < 5ºC is an inequality that compares temperatures.

B is the correct answer for the multiple choice question.

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