CHAPTER 16 - INTEGRATED ALGEBRA B



ALGEBRA UNIT 12- UNIVARIATE STATISTICS

Introduction to Statistics (Day 1)

Statistics is all about data. Without data to talk about or to analyze or to question, statistics would not exist. There is a story to be uncovered behind all data - a story that has characters, plots, and problems in the data. The questions or problems addressed by the data and their story can be disappointing, exciting, or just plain ordinary! This unit is about stories that begin with data.

Data: ___________________________________________________________________

Statistics: _______________________________________________________________

There are usually three steps in a statistical study:

1. The collection of ______________.

2. The organization of data into __________, _____________, and ____________.

3. The drawing of _________________ from an analysis of data.

Here are some ways to organize data:

Dot plots: ______________________________________________________________________________

1. What does this graph tell us about who watched this television show?

2. Can you make a conclusion about the type of show this data is about?

Frequency Histograms: _________________________________________________________________

____________________________________________________________________________

Cumulative Frequency Histogram: ______________________________________________________

____________________________________________________________________________

3. Is this a frequency histogram or a cumulative frequency histogram?

4. What do you think this graph is telling us about the population of Kenya?

5. Why might we want to study the data represented by this graph?

6. Based on your previous work with histograms, would you describe this histogram as representing a symmetrical or a skewed distribution? Explain your answer.

Box Plots: ______________________________________________________________________________

______________________________________________________________________________

7. What does the box plot tell us about the number of pets owned by the thirty students at Binder City High School?

8. Why might understanding the data behind this graph be important?

9. What percent of the people in this experiment have 0 – 1 pets? 0 – 2? 0 – 5? 0 – 10?

**Remember**

• Think of each graph as telling a story

• Graphs of distributions are often the starting point in understanding the variability in the data.

• The types of graphs in the previous exercises will be analyzed in more detail in the days that follow!

MEASURES OF CENTER AND SPREAD (Day 2)

• Mean ([pic]): The _________ of the data values _______________ by how many values.

• Median (Q2 or ____%): The _____________ value when data is in _____________!!!

o If there is no single middle number, take the average of the two middle numbers.

• Mode: The data value that ____________________________ occurs.

o No mode: If each number in a set of data occurs with the same frequency.

o Bimodal: When a set of data has two modes.

Quartile: When data is in numerical order, the number that separates data into _____ equal parts.

• 1st Quartile (Q1 or Lower Quartile or ____%): The ___________________ of the _________________ half.

• 3rd Quartile (Q3 or Upper Quartile or ____%): The ___________________ of the _________________ half.

Range: The __________________________ between the _____________________ and ______________________ data values.

Interquartile Range (IQR): The __________________________ between _____ and _____.

Data Set 1: Pet owners

Students from Binder City High School were randomly selected and asked, “How many pets do you currently own?” The results are recorded below:

1. Calculate the mean number of pets owned by the thirty students from Binder City High School. Calculate the median number of pets owned by the thirty students. Calculate the mode.

Data Set 2: Length of the east hallway at Binder City High School

Twenty students were selected to measure the length of the east hallway. Two marks were made on the hallway’s floor, one at the front of the hallway and one at the end of the hallway. Students were asked to use their meter sticks to determine the length between the marks to the nearest tenth of a meter. The results are recorded below:

Now it’s your turn!! Create a dot plot for the data above.

1. Why do you think that different students got different results when they measured the same distance of the east hallway?

2. Calculate the mean, median, and mode for this data.

Data Set 3: Age of cars

Twenty-five car owners were asked the age of their cars in years:

Make a dot plot for the ages of cars:

1. Describe the distribution of the age of cars. Find the median and mean. Would you use the median or the mean to describe a typical age of a 25-year old car? Why??

VARIABILITY/DEVIATION (Day 3)

Warm-up: Twenty-two students from the junior class and twenty-six students from the senior class at River City High School participated in a walkathon to raise money for the school’s band. Dot plots indicating the distances in miles students from each class walked are shown below:

Estimate the mean for both graphs and put an “X” where you think it is.

What is the median distance for the seniors?

What is the median distance for the juniors?

Would you use the mean or median to describe the typical distance for the seniors? Why?

Would you use the mean or median to describe the typical distance for the juniors? Why?

Variability: ___________________________________________________________________________

Deviation: ___________________________________________________________________________

|Life (Hours) |83 |94 |

|41 – 50 | | |

|51 - 60 | | |

|61 - 70 | | |

|71 - 80 | | |

|81 – 90 | | |

|91 - 100 | | |

|Total Frequency: |

A. Complete the table and construct a frequency histogram below.

B. Find the mean and median for the data. Then, indicate where they fall on the histogram, using arrows.

C. What is the shape of the distribution? Is it symmetric, skewed to the right, or skewed to the left?

Example 2: Label each graph as skewed right, skewed left, or symmetric.

Cumulative Frequency Histogram: A ________________ that displays the accumulation of data from the ____________ interval of data to the _______________.

• To find the cumulative frequency for each interval, ________ the frequency for that interval to the frequencies of the ______________ intervals.

Example 3: Construct a cumulative frequency histogram showing 8 intervals for these test grades:

100, 93, 71, 74, 85, 56, 62, 68, 70, 100, 99, 85, 77,

85, 48, 51, 79, 25, 86, 93, 67, 88, 70, 100, 26

|Test Scores (Intervals) |Tally |Frequency |Cumulative Frequency |

| | |(Number of Scores) | |

| | | | |

| | | | |

| | | | |

| | | | |

| | | | |

| | | | |

| | | | |

| | | | |

B. How many students scored below a 61?

C. Which interval(s) have the greatest number of students?

D. What percent of these 25 grades were above 70?

E. Which 10-point interval contains the median?

BOX (AND WHISKER) PLOTS (Day 5)

RECALL:

Median: When data is in numerical order, the number that separates data into _____ equal parts.

Quartile: When data is in numerical order, the number that separates data into _____ equal parts.

Procedure:

1. Arrange data from lowest to greatest

2. Find median (Second quartile/Q2)

3. Find First quartile (Lower quartile/Q1) - median of lower numbers

4. Find Third quartile (Upper quartile/Q3) - median of upper numbers

Interquartile Range: The _______________ between the __________ quartile (Q __ ) and

the ___________ quartile (Q __ ).

Example 1: The heights, in inches, of 20 students are shown in the following list. Find:

53, 60, 61, 63, 64, 65, 65, 65, 65, 66, 66, 67, 67, 68, 69, 70, 70, 71, 71, 73

a. The median c. The third quartile

b. The first quartile d. The interquartile range

Example 2: Using the following data, find the following with the help of your calculator.

8, 5, 12, 9, 6, 2, 14, 7, 10, 17, 11, 8, 14, 5, 6

c. The median c. The third quartile

d. The first quartile d. The interquartile range

BOX-AND-WHISKER PLOT :

5-number statistical summary: ________________, _________________, ________________,

__________________, and ___________________.

EXAMPLE 3:

A. Find the five statistical summary for the following set of data using your calculator:

Example 3: A data set consisting of the number of hours each of 40 students watched television over the weekend has a minimum value of 3 hours, a Q1 value of 5 hours, a median value of 6 hours, a Q3 value of 9 hours, and a maximum value of 12 hours. Draw a box plot representing this data distribution.

2. What is the interquartile range (IQR) for this distribution? What percent of the students fall within this interval?

3. Do you think the data distribution represented by the box plot is a skewed distribution? Why or why not?

Example 4: For the following data, construct a box plot:

8, 5, 12, 9, 6, 2, 14, 7, 10, 17, 11, 8, 14, 5

UNIVARIATE STATISTICS REVIEW (Day 6)

Example 1: Enter the following set of data into your calculator to construct a box and whisker plot.

71, 68, 74, 80, 71, 30, 73, 67, 75, 74, 67, 68, 72, 69, 71

2. What is the interquartile range (IQR) for this distribution? What percent of the students fall within this interval?

3. Do you think the data distribution represented by the box plot is a skewed distribution? Why or why not?

Example 2: The accompanying histogram shows the heights of the students in Kyra’s health class.

What is the total number of students in the class?

(1) 5 (2) 16 (3) 15 (4) 209

Example 3: The following shows the grades of 10 students on three different quizzes.

a) On which quiz did the students tend to do the poorest?

b) Find the following for the data on quiz 1:

Mean = Range =

Median = Standard Deviation =

Example 4: Twenty students were surveyed about the number of days they played outside in one week. The results of this survey are shown below. [6 pts.]

6, 5, 4, 5, 0, 7, 1, 5, 4, 4, 3, 2, 2, 3, 2, 4, 3, 4, 0, 7

|Interval |Tally |Frequency |Cumulative Frequency |

|0 – 1 | | | |

|2 – 3 | | | |

|4 – 5 | | | |

|6 – 7 | | | |

On the grid, create a cumulative frequency histogram based on the table you made.

-----------------------

Procedure to get Stat Measures using the Graphing Calculator:

1. Go to STAT, pick #1 (EDIT) - input stats into a list ([pic])

2. Go to STAT ( CALC, pick #1 (1-VAR STATS) {this gives you stats for 1 variable)

3. After 1-VAR STATS put L1 to indicate what list the data is in. (This may change)

Symbols to remember:

___________________, ___________________, ___________________, ___________________, ___________________

[pic]

[pic]

[pic]

[pic]

Skewed to the Left or

Symmetric or

Normal Distribution

Skewed to the Right or

[pic]

[pic]

[pic]

[pic]

a.

c.

b.

d.

[pic]

Procedure to get 5-number summary using the Graphing Calculator:

1. Go to STAT, pick #1 (EDIT) - input stats into a list

2. Go to STAT ( CALC, pick #1 (1-VAR STATS) {this gives you stats for 1 variable)

3. After 1-VAR STATS put L1 to indicate what list the data is in. (This may change)

Symbols to remember:

___________________, ___________________, ___________________, ___________________,

___________________

Procedure for drawing a Box and Whisker Plot

1. Determine 5 number summary using calc or by hand

2. Draw a scale with numbers from the minimum to the maximum value of a set of data.

3. Place dots at the values of the five number statistical summary.

4. Draw a box between the dots that represent the lower and upper quartiles, and a vertical line in the box through the point that represents the median.

5. Add the whiskers by drawing a line segment from the minimum value to the box and a line segment from the maximum value to the box.

[pic]

[pic]

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download