If there are 27 students in one class, how many are there in 5 classes?

Find the slope of the line.

Georgia [21]

Answer:

$\displaystyle m=1$

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

Brackets
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

Left to Right

Algebra I

Slope Formula: $\displaystyle m=\frac{y_2-y_1}{x_2-x_1}$

Step-by-step explanation:

Step 1: Define

Point (-4, -1)

Point (1, 4)

Step 2: Find slope m

Simply plug in the 2 coordinates into the slope formula to find slope m

Substitute [SF]: $\displaystyle m=\frac{4+1}{1+4}$
Add: $\displaystyle m=\frac{5}{5}$
Divide: $\displaystyle m=1$

4 0

3 years ago

The number of motor vehicles registered in millions in the US has grown as follows:

zysi [14]

Answer:

a) Figure attached

b) $r=\frac{n(\sum xy)-(\sum x)(\sum y)}{\sqrt{[n\sum x^2 -(\sum x)^2][n\sum y^2 -(\sum y)^2]}}$

For our case we have this:

n=10 $\sum x = 75.819, \sum y = 43.5231, \sum xy = 330.0321, \sum x^2 =574.8598, \sum y^2 =192.8274$

$r=\frac{10(330.0321)-(75.81948)(43.5231)}{\sqrt{[10(574.8598) -(75.819)^2][10(192.8274) -(43.5231)^2]}}=0.989$

So then the correlation coefficient would be r =0.989

Step-by-step explanation:

Previous concepts

The correlation coefficient is a "statistical measure that calculates the strength of the relationship between the relative movements of two variables". It's denoted by r and its always between -1 and 1.

Solution to the problem

Part a

Year (x): 1940, 1945 1950, 1955, 1960, 1965, 1970, 1975, 1980, 1985

Vehicles (Y): 32.4, 31.0, 49.2, 62.7, 73.9, 90.4, 108.4, 132.9, 155.8, 171.7

After apply natural log for the two variables and create the scatterplot in excel we got the following result on the figure attached.

Part b

And in order to calculate the correlation coefficient we can use this formula:

$r=\frac{n(\sum xy)-(\sum x)(\sum y)}{\sqrt{[n\sum x^2 -(\sum x)^2][n\sum y^2 -(\sum y)^2]}}$

For our case we have this:

n=10 $\sum x = 75.819, \sum y = 43.5231, \sum xy = 330.0321, \sum x^2 =574.8598, \sum y^2 =192.8274$

$r=\frac{10(330.0321)-(75.81948)(43.5231)}{\sqrt{[10(574.8598) -(75.81948)^2][10(192.8274) -(43.5231)^2]}}=0.989$

So then the correlation coefficient would be r =0.989

4 0

3 years ago

How long to cook a 22 pound ham at low temperature in an oven

Reil [10]

Directions

1. Preheat the oven to 350 degrees F (175 degrees C).

2. Place ham in a roasting pan, and press whole cloves into the top at 1 to 2 inch intervals. ...

3. Bake for 4 1/2 to 5 hours in the preheated oven (about 22 minutes per pound), or until the internal temperature of the ham has reached 160 degrees F (72 degrees C).

4 0

3 years ago

Lynn paid $17.25 for ribbon. The cost of the ribbon was $0.75 per foot. How many feet of ribbon did

snow_tiger [21]

Answer: 23

Step-by-step explanation:

1. Divide the amount Lynn paid for the ribbon, 17.25, by the amount the ribbon cost per foot, 0.75, to get how many feet of ribbon she bought.

17.25 / 0.75 = 23

7 0

2 years ago

Read 2 more answers

Rita wants to buy a rocking chair for $160 she will pay 10% down and pay the rest and six monthly installments what will be the

VLD [36.1K]

The amount for deposit is (10/100) × 160 = 16 So the remaining amount to pay is 160 - 16 = 144 and has to be paid within six months. 6 months --> 144 So 1 month ---> 144/6 = $24

5 0

3 years ago