Which measure of central tendency is found by dividing the sum of the entries by the number of entries?
Mean
100
Name 3 types of distribution graphs and explain how you graph one of them.
Stem and Leaf, Dot Plot, histogram
Dot Plot- use a number line with the first number being one before the smallest number and the last number as one more after the largest number. Plot dots according to the frequency. Name the number line and give the graph a title.
100
What is the definition of Standard Deviation?
The average distance away from the mean.
100
Construct a stem and leaf plot for the following data values:
73, 42, 67, 78, 99, 84, 91, 82, 86, 94
(Everyone must do it)
Show Ms. Barrett
100
What is the symbol for sample variance?
s squared
200
Which measure is easily changed by changing 1 data value in your set?
Mode
200
Explain what a skewed left and right shaped distribution look like.
Skewed left- there is a tail to the left, meaning there is less frequency on the left side and it drastically builds.
Skewed right- there is a tail to the right. It starts off with greater frequency and drastically decreases.
200
What is the symbol for sample and population standard deviation?
s and lower case sigma
200
What can the standard deviation never be? Why?
negative, because a distance can't be negative.
200
What is the difference between the range and the midrange?
The range is the difference between the largest and smallest number. The midrange is the average between the two.
300
Find the median of the following data values:
8, 4, 7, 9, 3, 3, 7, 6, 10, 2
6.5
300
What does a uniform distribution look like?
Every class has an equal frequency, so all the bars have the same height.
300
What does it mean to have a small or large standard deviation?
The larger the standard deviation, the larger the variation. The smaller the standard deviation, the smaller the variation.
300
What are outliers? Which measure of central tendency is the most resistant?
A value that "lies outside" (is much smaller or larger than) most of the other values in a set of data.
Median
300
What is the formula for sample mean using only the symbols?
x bar = sigma x / n
400
What is the symbol for sample mean and the symbol for population mean. (must know how to say it as well)x bar, mu
x bar, mu
400
Give an example of when a distribution might be bimodal.
Grades of students.
400
List all 6 steps to finding standard deviation by hand.
1. Find the mean for the data
2. Find the deviation for each data value (difference from the mean)
3. Square each of the deviations
4. Find the sum of the squares
5. Divide by n-1 (n= number of values)
6. Take the square root of the variance to get the standard deviation
400
How do you calculate the trimmed mean?
1. Put the values in order
2. multiply the percent by the amount of values
3. trim off the necessary values from beginning and end
4. recalculate the new mean
400
I have 5 data values with a mean of 36.6. 4 of the values are 25, 62, 39, and 16. What is the missing value?
41
500
Calculate the mean of the following data values:
210, 223, 189, 170, 205, 242, 182, 195, 190, 211, 261
207.1
500
Without graphing our data values, how can you tell whether or not a distribution will be skewed right/left or symmetric?
Skewed left- mean median> mode
Symmetrical- mean=median=mode
500
Find the variance for the following set of values:
22 39 15 48 61 50
310.1
500
Calculate the 10% trimmed mean of the following data values:
5, 4, 7, 6, 8, 10, 11, 0, 7, 18