Equations
Vocabulary
Probability
Data
100
How to find z?
100
what is the core meaning of a Null Hypothesis and Alternative Hypothesis?
Null Hypothesis (Hâ‚€)No change, no effect, no difference.
Alternative Hypothesis (Ha) a change, an effect, or difference.
100
What is the probability of flipping a fair coin and getting Tails?
0.5 (or 1/2 50%)
100
Finding the Mean
Question: What is the mean of the dataset: 3, 7, 8, 5, 12?
Add the numbers together (3 + 7 + 8 + 5 + 12 = 35). Divide the sum by the total number of data points(35/5 = 7)
200
What does the word sample mean?(Give an example!)
A smaller, representative subset of the population that is actually measured or observed to collect data (example, 1,000 randomly selected voters). [1]
200
If the probability that it will rain tomorrow is 0.3, what is the probability that it will not rain tomorrow?
0.7 (or 70%)
Work: The sum of all possible outcomes must equal 1.
1-0.3=0.7 or 70%
200
Finding the Median
Question: What is the median of the dataset: 14, 3, 9, 21, 7, 2?
First, arrange the numbers in order from smallest to largest: 2, 3, 7, 9, 14, 21. Because there is an even number of data points (6 points), take the average of the two middle numbers, 7 and 9 then divide by 2 = 8)
300
What does the word variable mean in Statistics?( give an example too!)
Variable: Any characteristic, number, or quantity that can be measured, counted, or categorized (an example is age, income, or hair color).
300
You roll a single fair six-sided die. What is the probability of rolling an even number?
1/2 (or 0.5 / 50%)
Work: Total outcomes:6 Even outcomes: 3
Probability: 3/6=1/2.
300
Finding the Range
Question: What is the range of the dataset: 45, 12, 89, 34, 76, 23?
Subtract the minimum value from the maximum value. The maximum is 89 and the minimum is 12 (89 - 12) = 77
400
What does the word parameter mean?
A fixed numerical value that describes an entire population (example the true average height of all adult women).
400
A bag contains 3 red marbles and 7 blue marbles. If you pick one marble at random, what is the probability it is red?
0.3 (or 3/10 /30%)
Work: Total marbles: 10 Red marbles: 3
Probability: 3/10 =0.3
400
A bag contains 4 red marbles, 3 blue marbles, and 5 green marbles. What is the probability of randomly picking a blue marble?
First, find the total number of marbles (4 + 3 + 5 = 12). Put the number of favorable outcomes over the total outcomes 3/12, which simplifies to 1/4 or 0.25.
500
What does the word variance mean or measures?
A measure of how spread out the data points are from their calculated mean value.
500
You flip a fair coin twice. What is the probability of getting heads on both flips?
1/4 (or 0.25 / 25%)
Work: Probability of Heads on flip 1 and 2 = 1/2
Multiply independent events: 1/2 X 1/2 = 1/4
500
Identifying the Mode
Question: What is the mode of the dataset: 5, 12, 5, 8, 12, 3, 12, 9?
Count how often each number appears. The number 5 appears twice, and the number 12 appears three times. Because 12 appears the most frequently, it is the mode.