3.) Given the graph of the line represented by the equation f(x) = -3x + b,

A photographer charges $12 for a set of 20 pictures. Each picture cost the same amount. At this rate, how many pictures cost $30

never [62]

Answer:

Step-by-step explanation:

20/12 = 1 2/3

30 ÷ 1 2/3

= $18

3 0

2 years ago

The following scatter plot shows the number of page views for a popular website and how many people signed up to receive emails

My name is Ann [436]

Answer:

See Explanation.

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
Subtract Property of Equality

Algebra I

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

Slope-Intercept Form: y = mx + b

m - slope
b - y-intercept

Linear Regression

Step-by-step explanation:

We can draw any best line of fit, as long as it is reasonable around the points that are given.

We can just take 2 points and use slope formula and Slope-Intercept Form to find the equation for the best line of fit.

Using Linear Regression, we can determine the true best line of fit using graphing utilities.

Finding the best line of fit

Define 2 points

Point (21600, 205)

Point (27000, 290)

Find slope m

Substitute in point [SF]: $\displaystyle m=\frac{290-205}{27000-21600}$
[Fraction] Subtract: $\displaystyle m=\frac{85}{5400}$
[Fraction] Simplify: $\displaystyle m=\frac{17}{1080}$

Find equation

Define equation [SIF]: $\displaystyle y = \frac{17}{1080}x + b$
Substitute in point: $\displaystyle 290 = \frac{17}{1080}(27000) + b$
Multiply: $\displaystyle 290 = 425 + b$
Isolate y-intercept b: $\displaystyle -135 = b$
Rewrite: $\displaystyle b = -135$
Redefine equation: $\displaystyle y = \frac{17}{1080}x - 135$

Slope-Intercept Form tells us that our slope m = $\displaystyle \frac{17}{1080}$ and our y-intercept $\displaystyle b = -135$ .

Setting this as function f(x), we can see from the graph that it is extremely accurate (Blue line).

Using Linear Regression

Depending on the graphing calc you have, the steps may be different.

Using a graphing calc, we can use statistics and determine the best best line of fit.

When we determine the values, we should see that our equation would be g(x) (Green Line).

Credit to Lauren for collabing w/ me in graphing.

6 0

3 years ago

An article written for a magazine claims that 78% of the magazine's subscribers report eating healthily the previous day. Suppos

Schach [20]

Answer:

89.44% probability that less than 80% of the sample would report eating healthily the previous day

Step-by-step explanation:

We use the binomial approximation to the normal to solve this question.

Binomial probability distribution

Probability of exactly x sucesses on n repeated trials, with p probability.

Can be approximated to a normal distribution, using the expected value and the standard deviation.

The expected value of the binomial distribution is:

$E(X) = np$

The standard deviation of the binomial distribution is:

$\sqrt{V(X)} = \sqrt{np(1-p)}$

Normal probability distribution

Problems of normally distributed samples can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

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

When we are approximating a binomial distribution to a normal one, we have that $\mu = E(X)$ , $\sigma = \sqrt{V(X)}$ .

In this problem, we have that:

$p = 0.78, n = 675$

So

$\mu = E(X) = np = 675*0.78 = 526.5$

$\sigma = \sqrt{V(X)} = \sqrt{np(1-p)} = \sqrt{675*0.78*0.22} = 10.76$

What is the approximate probability that less than 80% of the sample would report eating healthily the previous day?

This is the pvalue of Z when $X = 0.8*675 = 540$ . So

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{540 - 526.5}{10.76}$

$Z = 1.25$

$Z = 1.25$ has a pvalue of 0.8944

89.44% probability that less than 80% of the sample would report eating healthily the previous day

8 0

4 years ago

I need help. Thank you.

Oduvanchick [21]

Answer:

D

A=-5

Step-by-step explanation:

4 0

3 years ago

Read 2 more answers

I do not understand how to work out this question please help

enot [183]

a) To find the missing side length on triangle A, we can use the Pythagorean theorem.

a^2 + 12^2 = 13^2

a^2 + 144 = 169

a^2 = 25

a = 5 cm

5 and 12 = 5 and 12

b) The two triangles are congruent because they have two side lengths in common. If at least two side lengths are the same on two triangles, then they are congruent. In addition, these triangles have one angle in common as well.

Hope this helps!! :)

8 0

3 years ago