What are the 5 kinds of Samples?
Simple, Stratified, and Systematic Random Samples
Convenience Sample
Voluntary Response
X/3 = 27/9
x=9
If 3 out of 4 students like gum, estimate how many students would like gum in a class of 28 kids
21 students
What does the middle line of a box plot represent?
The Median
5x-3=17
X = 4
This type of Sample is when members are selected EVERY NTH person/thing
Systematic Random Sample
x/9 = 15/45
x=3
60% of adults say they like going to bed early. In a room of 130 adults, how many like to go to bed early?
78 Adults
Interquartile Range
There is a 14% tax to pay on auto parts. How much tax would you pay on a set of tires that cost $800?
$112
What makes a sample a Voluntary Response sample?
When it is optional to do, such as when it is on paper or in text format (online).
12/x = 8/24
x=36
A scientist is trying to estimate how many bears live in the mountains. She tags 40 bears, then over the next few months she takes samples of the population and finds on average, 2 out of 10 bears have tags on them. Estimate how many bears live in the mountain.
200 Bears
What is the mean of this Dot Plot? Round to the nearest tenth. (Picture 4.3)
6
4(-x+3)=36
x = -6
This type of sample is when members of a population are divided up into groups then randomly selected from those groups
Stratified Random Sample
A recipe calls for 2 cups of sugar for every 3 cups of flour. How much Sugar is needed for 7.5 cups of flour?
5 cups of sugar
A researcher wants to find out the prevalence of falcons in her small town. She puts tags on 50 of them, then studies over the next few months how many tags/falcons she sees. She finds that roughly 1 out of every 200 falcons have a tag on them. About how many falcons live in her town?
10000 Falcons
Its data is more consistent
A store marks up all of its prices by 35%. If a tub of margarine cost $4.95, how much does it cost now?
$6.68
Describe a Convenience Sample
If 5 kg of grapes cost $15, how much does 13kg of grapes cost?
$39.00
A Biologist wants to know how many worms live in his backyard. He (arguably inhumanely) colors 300 of them with crayons. After months of monitoring, he finds he only colored about 5% of the worms. How many worms are there total?
6000 Worms
A box plot is segmented into sections (separated by what are called Quartiles). How much of the data does each section represent, no matter the size of it?
25% of the data per section
x = 11