# You need to know the average age of students at McEachern High School. What do you think is the best way to find out this information?

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You need to know the average age of students at McEachern High School. What do you think is the best way to find out this information?

Analyze Surveys and Samples EQ: How can you identify populations and sampling methods?

Survey- Population- Sample- Random Sample- Biased Sample- A study of one or more characteristics of a group The entire group you want info about A part of the population Every member of pop. has an equal chance of being selected Not representative of the population

Simple Random Sample: Each individual is chosen entirely by chance, such that each individual has the same probability of being chosen at any stage during the sampling process. Putting a number in a hat for each class mate and then drawing one number. NOT – Choosing all residents on a randomly chosen street.

A group of students at our school wants to gather information about the need for additional funding for the school library. They survey every third person in A lunch.

The owners of an ice cream shop want to determine whether or not they should keep their stores open an hour later. They survey the customers in one of their stores.

Create a survey (question) about a topic that interests you. Explain how you would give the survey so that it is random.

You MUST organize your data set FIRST!!!! 2, 1, 4, 5, 2, 3, 5, 1, 5, 5, 2 Data Set: ( 2, 1, 4, 5, 2, 3, 5, 1, 5, 5, 2 ) 1, 1, 2, 2, 2, 3, 4, 5, 5, 5, 5 ( 1, 1, 2, 2, 2, 3, 4, 5, 5, 5, 5 )

The range of the data set is the difference between the largest and smallest number in the set. To find the range, you simply subtract the smallest number from the largest number in the set. Range = 5 – 1 = 4 Calculate Calculate: CRUNCH the numbers! 1, 1, 2, 2, 2, 3, 4, 5, 5, 5, 5 ( 1, 1, 2, 2, 2, 3, 4, 5, 5, 5, 5 )

The mean of the data set is its average. To find the mean you add up all the numbers and divide the answer by how many numbers you have. Mean = 3.18 1, 1, 2, 2, 2, 3, 4, 5, 5, 5, 5 ( 1, 1, 2, 2, 2, 3, 4, 5, 5, 5, 5 )

The Median is the number which is in the exact middle of the data set. Median = 3 1, 1, 2, 2, 2, 3, 4, 5, 5, 5, 5 ( 1, 1, 2, 2, 2, 3, 4, 5, 5, 5, 5 )

The Mode is the number that appears the most often. Mode = 5 1, 1, 2, 2, 2, 3, 4, 5, 5, 5, 5 ( 1, 1, 2, 2, 2, 3, 4, 5, 5, 5, 5 )

Example 1: Find the range, mean, median, and mode for the following data set. (4, 8, 6, 10, 4, 2)

Example 2. Two dice were thrown 10 times and their scores were added together and recorded. Find the mean, median, mode and range for this data. 7, 5, 2, 7, 6, 12, 10, 4, 8, 9

Example 3. Nine people took a vocabulary test. Their scores (out of 10) are recorded below. Find the mean, median, mode and range for the test. 2, 9, 3, 7, 4, 8, 6, 10, 4

Example 4. The number of matches in a random sample of 11 boxes were counted and the results are recorded below. Find the mean, median, mode, and range of the data. 49, 50, 51, 49, 49, 55, 47, 52, 51, 50, 51

2, 1, 4, 5, 2, 3, 5, 1, 5, 5, 2 1)Find the range, mean, median and mode. 2)Which measure above best represents the team’s typical margin of victory? The margin of victory for the MHS lacrosse team in its last wins is: Example 5. The margin of victory for the MHS lacrosse team in its last wins is:

Calculate: crunch the numbers Quartiles: Q1 is the first quartile (or 25 th percentile). Find the median of the bottom half of numbers. Q3 is the third quartile (or 75 th percentile). Find the median of the top half of the numbers. INTERQUARTILE RANGE: Q3 – Q1

Example 2(again) Two dice were thrown 10 times and their scores were added together and recorded. Find Q1 and Q3 and the IQR. Find Q 1 and Q 3 and the IQR of each of the previous class examples. 7, 5, 2, 7, 6, 12, 10, 4, 8, 9 2, 4, 5, 6, 7, 7, 8, 9, 10, 12 Lower Quartile = 5 Q1Q1 Upper Quartile = 9 Q3Q3 Median = 7 Q2Q2 Inter- Quartile Range = 9 - 5 = 4

5 Number Summary Used in Statistics to analyze the data set. It can help you compare more than one data set by seeing the characteristics of each data set in an organized way. We need the 5 number summary in order to construct a box plot.

Constructing Boxplots Using a 5 number summary: 1.The minimum value 2.Q 1 3.Median 4.Q 3 5.The maximum value

The numbers below represent the number of homeruns hit by players of the McEachern baseball team. 2, 3, 5, 7, 8, 10, 14, 18, 19, 21, 25, 28 Q 1 = 6Q 3 = 20 Interquartile Range: 20 – 6 = 14 12206

Steps to constructing a box plot 1.Arrange the data set in order. 2.Calculate mean, median, Q 1, Q 3, IQR, and absolute mean deviation. 3.Use the 5 number summary to construct a boxplot. 4.Comment on what you notice.

Example 2(again-again) Two dice were thrown 10 times and their scores were added together and recorded. Find Q1 and Q3 and the IQR. 7, 5, 2, 7, 6, 12, 10, 4, 8, 9 Construct a box plot using the information from ONE of the other class examples.

Robert hit 12 golf balls at the driving range. The recorded distances of his drives, measured in yards, are given below. Find the measures of central tendency, then construct a box plot of the data. 85, 125, 130, 65, 100, 70, 75, 50, 140, 135, 95, 70 TURN IN BEFORE YOU LEAVE!!!

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