6-1 Populations and Samples
How do you find a representative sample of a population?
Any form of random selection from the population.
51/60 people sad they wanted Alicia's T-shirt in a survey in a school of 300 people. About how many shirts should she order? Show work.
255 T-shirts
How can displays of data be used to compare one population to another?
You can visualize the data and compare.
A dot plot of push ups shows data 28 through 36 what is the range?
The range is 8
Why does a sample need to be representative of a population?
So you can draw valid inferences about the population.
The owner of a candy company surveys everyone who goes to the candy shop on a Wednesday to see if peanut brittle or fudge is more popular. Is this a representative population?
No he only picked people on a Wednesday.
Why can you use a random sample to make an inference?
It represents the population.
What measures of variabilities are used when comparing box plots?
Iqr, Range, and median
Jeffery has a MAD of 3 hours of cooking. while his sister patrisha has 3.2. who has more variability?
Patrisha
A shoe company conducts a survey to find an approximate number of it's buyers who like Jordan 1's. What is the population of this survey?
The company's buyers.
If Johnny's water bottle company sells 3 colors and he has 270 customers. how could he get a representative sample?
Make form of a representative sample like a random name spinner.
Bryson runs a french fry company and 3 out of 5 food critics say it's incredibly good so he says they're the best. Is this inference valid.
No there is not enough surveys, they need more data.
Two towns have a median temperature amount of 14 degrees. town A has an IQR of 5 degrees and class B has an IQR of 3 degrees. which town has more variability
Town A has larger variability.
Adults have a mean of 4.8 hours of exercise while as teens have a mean of 7.6 hours of exercise. Who exercises more? Explain
Teens. They have a higher mean
Charlie wants to predict if people will like his grilled cheese sandwiches at his restraunt, so he puts random numbers to customers then picks them and calls them. Is this a representative sample
No, It is only people with phones who can get called.
A car company owner wants to know how many of its customers like how bmw's look, so he conducts a survey. What is the population?
The car companies customers.
About 363
Carter compares the low temperature in city 1 and city 2 for one week. In city 1 the range is 12 degrees and the IQR is 7 degrees and City 2 IQR is 7 degrees and the range is 22 degrees. Which is more consistent
Weather in city 1 is more consistent than city 2
2 groups of car can record their gas mileage and group 1 has a mean of 28 and group 2 has a mean of 31 while as group 1 has a mad of 1.8 while group 2 has a mad of 1.9. Group 1 has a range of 11 and group 2 has a range of 9. which one has more variability?
Group 2
Daqavius wants to find the number of students in his school that's favorite food is pizza. what is the population of his study?
All of the students.
Bridgers Labubu company I trying to find out if he sell more yellow labubus on a Wednesday or Thursday. So he checks at 6;30 am on a Wednesday and 6:30 pm on a Thursday. Is this representitive?
No, some people aren't awake at 6:30 am and some people go to bed before 6:30 pm
Dan collects data from a random sample of 4th graders and found 15 out of 20 students bring cold lunch if there is 300 students how many students would he expect to bring cold lunch?
If Box plot A and box plot B have range of 20 and A has an IQR of 6 and median of 17 and B has IQR of 5 and median of 16. which is more consistent?
B
1 group of toys works for an average of 12 months and groups 2 works for 24 months. Make an inference about the of the toys
group 2 lasts longer than group 1
No there is not enough people and they only picked one office.