topic 2
What is a ratio?
A ratio is a relationship in which for every x units of one quantity there are y units of another quantity.
10.75
There are red and yellow flowers in a city park. The number of yellow flowers is 3 more than 1/3 of the number of red flowers. There are 21 yellow flowers. Write an equation to find the number of red flowers.
r=54
What does MAD mean
Mean Absolute Deviation
Population
Group of people
How many feet in one day in 42.6/3
14.2/1
-7+1/3n-4/3+2n=?
2 1/3n - 8 1/3
2(4.3+n)=17.63
n=4.515
What is a representative sample
It accurately reflects the characteristics of the population
Additive inverses
two numbers that have a sum of 0
is 600/200, 1200/400, and 1500/500 a proportional relationship? (2-3)
Yes, because when divided they all equal 3/1.
Expand the expression 1/4(h+7)
(1/4 X H)+(1/4 x 7) = 1/4h + 1.75
x + 13 > 43
x > 30
What is a inference?
a conclusion about a population based on data from a sample or samples.
interest rate
interest is calculated based on a percent of the principal. That percent is called the interest rate
What is a rate?
a rate is a ratio that relates two quantities with different units.
The GCF of 12x, 15, and-9y is 3. Rewrite each term using 3 as a factor.
3(4x-3y+5)
solve-15n > 75
n < -5
What's a valid inference?
estimates that can be made about the population based on sample data.
invalid inference
an invalid inference is false about the population, or does not follow from the available data.
what is the constant of proportionality for 27/3h, 45/5h, and 54/6h, if h is hours and w is wages.
w=9h
The perimeter of a square is represented with the expression 84 + 44s. What is the length of one side of the square? 4 sides so factor out 4
4(21 + 11s)
7(x + 8) - 4 < 143.
x < 13
19 students said they like to read, 8 said they like to craft, 23 say they like to play sports. What can you infer about this data?
doing crafts is the schools least favorite.
Random Sample
In a random sample, each member in the population has an equal chance of being selected.