All categories

2 years ago

Find the equation of the line through the points (-2,1) and (5,-20)

Mathematics

1 answer:

ankoles [38]2 years ago

5 0

Answer:

y = -3x - 5

Step-by-step explanation:

First find the slope: (-20 - 1) / (5 - (-2)) = -3

Then plug in one set of points into the equation y = mx + b.

1 = -3(-2) + b

1 = 6 + b

b = -5

So you can get the equation: y = -3x - 5

You might be interested in

Past experience has indicated that the breaking strength of yarn used in manufacturing drapery material is normally distributed

vlabodo [156]

Answer:

95% two-sided confidence interval on the true mean breaking strength is (94.8cm, 99.2cm)

Step-by-step explanation:

Our sample size is 11.

The first step to solve this problem is finding our degrees of freedom, that is, the sample size subtracted by 1. So

$df = 11-1 = 10$ .

Then, we need to subtract one by the confidence level $\alpha$ and divide by 2. So:

$\frac{1-0.95}{2} = \frac{0.05}{2} = 0.025$

Now, we need our answers from both steps above to find a value T in the t-distribution table. So, with 10 and 0.025 in the two-sided t-distribution table, we have $T = 1.812$

Now, we find the standard deviation of the sample. This is the division of the standard deviation by the square root of the sample size. So

$s = \frac{4}{\sqrt{11}} = 1.2060$

Now, we multiply T and s

$M = Ts = 1.812*1.2060 = 2.19/tex]For the lower end of the interval, we subtract the sample mean by M. So the lower end of the interval here is[tex]L = 97 - 2.19 = 94.81 = 94.8$ cm

For the upper end of the interval, we add the sample mean and M. So the upper end of the interval here is

$L = 97 + 2.19 = 99.19 = 99.2$ cm

95% two-sided confidence interval on the true mean breaking strength is (94.8cm, 99.2cm).

7 0

3 years ago

An English professor assigns letter grades on a test according to the following scheme. A: Top 15% of scores B: Scores below the

lisabon 2012 [21]

Answer:

59 to 66

Step-by-step explanation:

Mean test scores = u = 74.2

Standard Deviation = $\sigma$ = 9.6

According to the given data, following is the range of grades:

Grade A: 85% to 100%

Grade B: 55% to 85%

Grade C: 19% to 55%

Grade D: 6% to 19%

Grade F: 0% to 6%

So, the grade D will be given to the students from 6% to 19% scores. We can convert these percentages to numerical limits using the z scores. First we need to to identify the corresponding z scores of these limits.

6% to 19% in decimal form would be 0.06 to 0.19. Corresponding z score for 0.06 is -1.56 and that for 0.19 is -0.88 (From the z table)

The formula for z score is:

$z=\frac{x-u}{\sigma}$

For z = -1.56, we get:

$-1.56=\frac{x-74.2}{9.6}\\\\ x = 59$

For z = -0.88, we get:

$-0.88=\frac{x-74.2}{9.6}\\\\ x = 66$

Therefore, a numerical limits for a D grade would be from 59 to 66 (rounded to nearest whole numbers)

7 0

3 years ago

Megan has $15,000 to invest. She is considering two investment options. Option A pays 3.2% simple interest. Option B pays 4.1% i

True [87]

wheee

Compute each option

option A: simple interest

simple interest is easy

A=I+P

A=Final amount

I=interest

P=principal (amount initially put in)

and I=PRT

P=principal

R=rate in decimal

T=time in years

so given

P=15000

R=3.2% or 0.032 in deecimal form

T=10

A=I+P

A=PRT+P

A=(15000)(0.032)(10)+15000

A=4800+15000

A=19800

Simple interst pays $19,800 in 10 years

Option B: compound interest

for interest compounded yearly, the formula is

$A=P(1+r)^t$

where A=final amount

P=principal

r=rate in decimal form

t=time in years

given

P=15000

r=4.1% or 0.041

t=10

$A=15000(1+0.041)^{10}$

$A=15000(1.041)^{10}$

use your calculator

A=22418.0872024

so after 10 years, she will have $22,418.09 in the compounded interest account

in 10 years, the investment in the simple interest account will be worth $19,800 and the investment in the compounded interest account will be worth$22,418.09

4 0

3 years ago

Read 2 more answers

Chris can be paid in one of two ways. Plan A is a salary of $490 per month, plus a commission of 9% of sales. Plan B is a sal

skad [1K]

Answer:

$390+0.07s=$544+0.05s Subtract $390 from each side.

0.07s=$154+0.05s Subtract 0.05s from each side.

0.02s=$154 Divide each side by 0.02.

s=$7700 Both plans pay the same when sales=$7700

ANSWER With sales greater than $7700, Chris is better off with Plan A.

5 0

3 years ago

A worker is handling the four of a rectangle room that is 12 feet by 15 feet.The tiles are square with side lengths 1 1/3 feet.

Anon25 [30]

Answer:

Step-by-step explanation:

The measure of the floor of the rectangular room that is 12 feet by 15 feet. The formula for determining the area of a rectangle is expressed as

Area = length × width

Area of the rectangular room would be

12 × 15 = 180 feet²

The tiles are square with side lengths 1 1/3 feet. Converting 1 1/3 feet to improper fraction, it becomes 4/3 feet

Area if each tile is

4/3 × 4/3 = 16/9 ft²

The number of tiles needed to cover the entire floor is

180/(16/9) = 180 × 9/16

= 101.25

102 tiles would be needed because the tiles must be whole numbers.

3 0

2 years ago