math 2 Flashcards
Primary Data
Primary Data is data I collected myself
Secondary Data
secondary data is collected by someone else.
How do you take primary data
Different ways of collecting primary data include questionairres, surveys and data logging
What is population
The total number of items your suevey relates to is called the population
What is a sample
The group of items you test is called a sample
For a sample to be reliable and unbiased, it should
be at least 10% of the population and represent the population
the more larger the sample
the more reliable it is
what is a random sample
A random sample, the whole population has an equal chance of being chosen, so it reduces the chances of being biased
A good question should not be
unclear
leading
restrictive
Leading question meaning
A leading question encourages people to give a particular answer
a grouped frequency table has how many classes?
4 or 5 equal width classes
When y and x are in direct proportion, what is constant?
y / x is constant
What is the symbol for proportion?
∝
if y and x are in proportion, what does the k mean in y=kx
when y ∝ x,then y =kx, the k is the constant of proportionality
percentage change formula
percentage change = actual change / original amount * 100
how do you say if something is inversely proportional?
y ∝ 1/x, y = k/x, applies the same for the opposite values (e.g x = …)
what do you do if a number is to the power of a fraction
a^(m/n)
(n squareroot(a))^m
What is a right prism
is a prism where the cross-section is at right angles to the length of the solid
what is perfect square
x^2 + 2ax + a^2
