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Ray Of Light [21]

3 years ago

9

Suppose that a regression line for some data transformed with logarithms predicts that when x equals 4, log(y) will equal 3.331.

What does the regression line predict y will equal when x equals 4? Round your answer to the nearest whole number.
A. 101

B. 13

C. 3

D. 2143

1 answer:

deff fn [24]3 years ago

7 0

Option D

The regression line predicts that at x = 4, y equals 2143

<em><u>Solution:</u></em>

Given that when x equals 4, log(y) will equal 3.331

To find: Find y when x equals 4

Since we have given that,

When x = 4,

$\text{ log } y = 3.331$

We need to find the value of 'y' when x = 4

$log_{10}y = 3.331$

Since it is logarithmic function with base 10, Raise to power of 10 on both sides,

$10^{log_{10}y} = 10^{3.331}\\\\\text{10 power log base 10 cancels, we get }\\\\y = 10^{3.331}\\\\y = 2142.89$

On rounding to nearest whole number, we get 2143

Thus Option D is correct

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In Δ A B C, the measure of the largest angle is 32 less than 3 times the smallest angle. The measure of the middle angle is 8 mo

AlladinOne [14]

Answer:

52degrees

Step-by-step explanation:

Let the measure of the largest angle be x

middle angle be y

smallest angle be z

Since the sum of angle in a triangle is 180 degrees, hence;

x + y + z = 180 .... 1

If the measure of the largest angle is 32 less than 3 times the smallest angle, then;

x = 3z - 32

3z = x+ 32

z = x+32/3 ..... 2

If he measure of the middle angle is 8 more than half the measure of the largest angle, then;

y = x/2 + 8 .... 3

Substitute 2 and 3 into 1;

x + x/2 + 8 + (x+32)/3 = 180

multiply through by 6

6x + 3x + 48 + 2(x+32) = 1080

9x + 48 + 2x + 64 = 1080

11x + 112 = 1080

11x = 1080-112

11x = 968

x = 968/11

x = 88 degrees

Get the middle angle y;

Since y = x/2 + 8

y = 88/2 + 8

y = 44 + 8

y = 52 degrees

Hence the measure of the middle angle is 52degrees

5 0

3 years ago

A festival charges $3 for child admission and $5 for adult admision. At the end of the festival they have sold 779 tickets for a

lutik1710 [3]

Answer:

562 child tickets were sold

217 adult tickets were sold

Step-by-step explanation:

A festival charges $3 for children admission and $5 for adult admission

At the end of the festival they have sold a total number of 779 tickets for $2771

Let x represent the child ticket

Let y represent the adult ticket

x + y= 779..............equation 1

3x + 5y= 2771..........equation 2

From equation 1

x + y = 779

x= 779 -y

Substitute 779-y for x in equation 2

3x + 5y= 2771

3(779-y) + 5y= 2771

2337 - 3y + 5y= 2771

2337 +2y= 2771

2y= 2771 -2337

2y = 434

y = 434/2

y = 217

Substitute 217 for y in equation 1

x + y= 779

x + 217= 779

x = 779-217

x= 562

Hence 562 child tickets were sold and 217 adult tickets were sold

6 0

4 years ago

1.) What is the equation of the path of firework #1? Write your equation in general form.

valina [46]

1. I'm assumig that the paths are perfect parabolas

this means that their general forms can be written in $y=ax^2+bx+c$

it's easier to find vertex form first then expand to get general form

vertex form is $y=a(x-h)^2+k$ where the vertex is (h,k) and a is a constant

firework #1

vertex is (10,50), so (h,k)=(10,50) and h=10, k=50

$h_1=a(t-10)^2+50$

to find the value of $a$ , subsitute another point

(0,0)

$0=a(0-10)^2+50)$

$0=100a+50$

$a=\frac{-1}{2}$

so the equation in vertex form is $h_1=\frac{-1}{2}(t-10)^2+50$

expand to get general form

$h_1=\frac{-1}{2}(t^2-20t+100)+50$

$h_1=\frac{-1}{2}t^2+10t-50+50$

$h_1=\frac{-1}{2}t^2+10t$

2.

same as last time

vertex is (10,72) so (h,k)=(10,72) so h=10 and k=72

equation is $h_2=a(t-10)^2+72$

find $a$

use another point

(0,22)

$22=a(0-10)^2+72$

$22=100a+72$

$-50=100a$

$a=\frac{-1}{2}$

so the equation in vertex form is $h_2=\frac{-1}{2}(t-10)^2+72$

3.

range is the numbers that h is allowed to be

think about what h represents. it represents the height of the rocket

from the graph, we can see that the lowest possible height is 0yd and the highest height is 50yd

so range is 0 to 50 or 0≤h≤50

domain is the numbers that t is allowed to be

think about what t represents. it represents how long the rocket has been flying

it will stop flying when it hits the ground or at t=20

it starts flying at t=0

so domain is from 0 to 20 or 0≤t≤20

3 0

3 years ago

Help me find my answer

Sergeu [11.5K]

Step-by-step explanation:

3 cookies= 240 cal

∴ 1 cookie= 240÷3 cal

∴ 5 cookies= (240÷3) × 5

⇒ 240÷3= 80

⇒ 80 × 5= 400

[ans] 400 cal

4 0

3 years ago

Solve the following system of equations. What is one x-value of a solution?

gulaghasi [49]

Answer:

There is some mistake in the question, because the solutions are x = -1.445 and x = -34.555

Step-by-step explanation:

Given the functions:

f(x) = x² + 4x + 10

g(x) = -32x - 40

we want to find the points at which f(x) = g(x).

x² + 4x + 10 = -32x - 40

x² + 4x + 10 + 32x + 40 = 0

x² + 36x + 50 = 0

Using quadratic formula:

$x = \frac{-b \pm \sqrt{b^2-4(a)(c)}}{2(a)}$

$x = \frac{-36 \pm \sqrt{36^2-4(1)(50)}}{2(1)}$

$x = \frac{-36 \pm 33.11}{2}$

$x_1 = \frac{-36 + 33.11}{2}$

$x_1 = -1.445$

$x_2 = \frac{-36 - 33.11}{2}$

$x_2 = -34.555$

5 0

3 years ago