Surveys and Samples
Which question is biased:
1- What is your favorite food for lunch?
2- Is pizza your favorite food for lunch?
2
What does frequency mean?
How often something happens or occurs.
How do you find the mean of a data set?
Add up the data and divide by the number of pieces of data.
Where is the median in a box-and-whisker plot?
Right in the middle of the box.
If you want to know how tall most people are in your class of 15 students, would you take a sample or ask the population?
Population
What is cumulative frequency?
A running total of the frequency
How do you find the range of the data?
Subtract the smallest piece if data from the largest.
What do the whiskers show in a box-and-whisker plot?
The extremes.
If you want to know how many teenagers wear glasses, who should you ask to get a representative sample?
1- High School Students
2- Residents at a Retirement Community
1
What is relative frequency?
The frequency of one thing compared to the whole.
How do you find the mode of the data?
Look for the number that repeats the most.
What does this key mean in a stem-and-leaf plot:
4 I 5 = 45
It means the stems represent tens and the leaves represent ones
Is there always a mode? Can there be more than 1 mode?
No and yes there can be more that one mode.
What is special about a histogram?
It has intervals and the bars touch.
How do you find the median? Does it make a difference if you have an odd or even number of data?
It's the number in the middle. If you have an even number of data you must find the average of the two numbers in the middle.
In a circle graph that represents 300 people, 1/10 of those people drive a yellow car. How many people drive a yellow car?
1/10 x 300 = 30