Central Tendency
What measure of central tendency is found by adding all values and dividing by the number of values?
Mean
The difference between the highest and lowest values
Range
What measures of relative position divide data into four equal parts?
Quartiles
What type of distribution is symmetrical and bell-shaped?
Normal distribution
It measures the relationship between two variables
Correlation
What is the formula for the population mean?
μ = Σx/N
where:
μ = population mean;
Σx = sum of all values;
N = total number of values
Measure that tells how spread out data values are from the mean
Standard deviation
Who developed the Box-and-Whisker Plot?
John Wilder Tukey
The measure of how likely an event is to happen.
Probabilty
A method used to model and predict the relationship between two variables.
Linear Regression
Find the mean of 4, 6, 8, 10
7
If the highest value is 45 and the lowest is 18, what is the range?
The range is 27
How many equal parts are created by quartiles?
4
What is the shape commonly associated with a normal distribution?
Bell-shaped curve
What is a positive correlation?
When one variable increases, the other also tends to increase.
Find the median: 12, 18, 15, 20, 14, 16, 10
15
How do you solve variance and sample standard deviation step-by-step?
1st Compute the mean
2nd Subtract the mean from each value
3rd Compute sample variance
4th Compute sample standard deviation
A class of 100 students has a mean of 75 and SD of 10. A student scored 85. Find the population z-score.
1
A bag contains 10 balls, including 4 red balls. What is the probability of picking a red ball?
40%
SOLVE:
y = 2x + 3, find y when x = 5
13
We have scores: 18, 25, 32, 21, 29, 35, 24, 31 and 27. If 35 belongs to another class, what is the population mean?
25.875 or 25.88
Temperatures are 18, 22 and 19. Find the sample variance (2 mins to solve)
The sample variance is 4.33
What is the difference between negatively and positively skewed distributions?
Negative skew: left whisker is longer.
Positive skew: right whisker is longer.
A test has a mean of 70 and SD of 5. A student scores 80. Find the z-score.
2
SOLVE:
y = 3x − 4, find y when x = 8
20