1.

Maddie is reading a graph of equivalent ratios. One point on the graph is (4, 5). Maddie says (10, 8) is also on the graph. Is M

dmitriy555 [2]

Yes and no, (4, 5) multiplied by 2 is (10, 8) but reversed. It depends on how you look at it because (10, 8) would be on the other side of the graph than (8, 10) which is the actually equivalent.

6 0

2 years ago

Read 3 more answers

While Sam was at work, his house lost electrical power. By the time the electrical power came back on, the temperature inside th

Lunna [17]

A) 30 minutes after the air conditioner started to cool the house, the temperature inside the house has dropped to 76°F

B) $f(x)=-0.4x+88$

Step-by-step explanation:

A)

In this problem, f(x) represents temperature, in degrees Fahrenheit, of Sam’s house x minutes after the air conditioner started to cool the house.

So we have:

x = minutes after the air conditioner started to cool the house

f(x) = temperature

Here we want to find what is the meaning of

$f(30)=76$

Which implies that:

$x=30$ , which means that 30 minutes have passed after the conditioner has started to cool the house

$f(x)=76$ , which means that the temperature of the room at that time is 76°F

So, the interpretation of f(30) =76 is that:

"30 minutes after the air conditioner started to cool the house, the temperature inside the house has dropped to 76°F"

B)

Here we want to write explicitely a function that tells us how the temperature inside the house varies as a function of x, the number of minutes passed after the air conditioner has turned on.

We know the following information:

- At time x = 0, the temperature inside the house is 88°F

- At time x = 30 min, the temperature inside the hosue is 76°F

We can assume that the temperature inside the house changes linearly with time; so, we can describe the temperature function with the equation of a line:

$f(x)=mx+q$

where

$q$ is the value of the temperature at x = 0, so q = 88

m is the rate of change of the temperature

The rate of change can be found by calculating the rate of change of the temperature with respect to the change in time; so we find:

$m=\frac{76-88}{30-0}=-0.4$

which means that the temperature decreases by 0.4°F every minute. So, the function can be written as

$f(x)=-0.4x+88$

4 0

2 years ago

The following estimated regression model was developed relating yearly income (y in $1000s) of 30 individuals with their age (x1

ira [324]

Answer:

$R^2 = \frac{SSE}{SST}=\frac{384}{1200}=0.32$

So the best option is b. .42

Step-by-step explanation:

Previous concepts

Analysis of variance (ANOVA) "is used to analyze the differences among group means in a sample".

The sum of squares "is the sum of the square of variation, where variation is defined as the spread between each individual value and the grand mean"

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. And is defined as:

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

When we conduct a multiple regression we want to know about the relationship between several independent or predictor variables and a dependent or criterion variable.

Solution to the problem

If we assume that we have $k$ independent variables and we have $j=1,\dots,j$ individuals, we can define the following formulas of variation: