Chapter 5
Find 11C10
11
What does a probability distribution for a discrete variable provide?
The possible values of the random variable and their corresponding probabilities. Table of graph or mathematical formula.
What is a frequency distribution?
lists each category of data and the number of occurrences for each category of data
What is mean, median and mode?
Mean-add all numbers and divide by the amount of numbers you have
Median-putting the numbers in order and finding the middle number
Mode- the number repeated the most.
How many ways can you re-arrange 6 students?
6! or 720
What is a random variable?
numerical measure of the outcome of a probability experiment, so its value is determine by chance.
What is a relative frequency?
frequency / sum of all frequencies
if a numerical summary of data is said to be resistant, what does that mean?
extreme values relative to the data do not affect its value substantially
What are the two rules for a probability model?
all probabilities need to add up to one
each probability is between 0 and 1
What is the difference between discrete and continuous random variable (s)?
discrete has either a finite or countable number of values.
Continuous has infinitely many values.
describe a bar graph?
labeling each category of data on either the horizontal or vertical axis and the frequency or relative frequency on the other side.
Name three distribution shapes?
skewed left and right also symmetric
What is the addition rule for disjoint Events
P(E or F)= P(E) + P(F)
describe a probability histogram?
the horizontal axis corresponds to the value of the random variable and the vertical axis represents the probability of each value of the random variable.
What is a class width when organizing continuous data in a table?
class width is the difference between consecutive lower class limits.
What does the standard deviation tell us?
what's the difference between a population standard deviation and sample deviation?
describe how far, on average, each observation is from the mean. ( deviation about the mean).
n-1 vs n (sample is not all the observations)
About 13% of the population is left-handed. If two people are randomly selected, what is the probability that both are left-handed?
What is the probability that at least one is right-handed?
0.0169
.9831
What is the formula for the mean of a random discrete variable?
sigma (X* P(X))
What does a stem-and leaf plot represents what?
quantitative data graphically
Describe what a z-score tells us?
tells us the distance that a data value is from the mean in terms of the number of standard deviations.