Math 8C Unit 6 – Statistics & Probability Standards Addressed: Determine if mean, median, or mode best represents center for a data set and explain why. Model and analyze data using box plots, bar graphs, histograms, and mean average deviation. Compare center for two or more sets of related data and explain how spread affects data. Describe the shape and spread of data using measures of variability (MAD), appropriate models, and account of extreme data points. Model and interpret data using a two-frequency table. Determine joint, marginal, and conditional frequency. Determine probability of conditional events modeled in a two-way frequency table Determine compound independent events Determine compound dependent events

Must Do (3/21): REVIEW! Find the line that is perpendicular to y = -3x+4 and passes through the point (-3,-10) Solve: 2𝑥−5 6−2𝑥 =3𝑥−2−9𝑥 Challenge! The word RUSTED is written over and over to form an infinite sequence. What is the 128th letter of the sequence? y=(1/3)x - 9 x = (14/9) U

Loop Review Handout #1 Why California? task

Must Do (3/22): In your Words Worth Knowing, write your definition of mean, median, and mode. (Leave space to write in a book definition later). The first term in a sequence is x and every term after is 2 less than twice the preceding term. If x>2, what is the ratio of the third term to the second term? 𝑥−1 𝑥−2 e) 𝑥−1 2𝑥−3 2𝑥−3 𝑥−1 4𝑥−2 𝑥−2 3𝑥+3 4𝑥 B

Must Do (3/23): 12 – n, 12, 12+n What is the average (arithmetic mean) of the 3 quantities in the list above? 2. 82, 42, 22, 12 The first term in the sequence above is 82, and each term after that is determined by dividing the previous term by x and then adding y. What is the value of y? 12 Y=1

Mean, Median and Mode Measures of Central Tendency Mean (average): The sum of all items then divided by the number of items. Add it all up and divide by how many you have Median: The exact middle of all items. Line all items up from least to greatest, and the value right in the middle is the median. Mode: The item or value that appears most often Might be bimodal, trimodal, or no mode Outlier: The value(s) in a set of data that is much smaller or much larger than the rest of the data.

for representing the center of the data? Which is best for representing the center of the data? Mean (average): Usually the best when there is no outlier. Median: Usually the best when there are outliers. Mode: Usually the best when you want to select the most popular value or data item.

Concept Review Find the mean, median and mode for the data: Mean: 30.7𝑘 or $30,700 Median: 15.5𝑘 or $15,500 Mode:$15 𝑘 or $15,000

Frequency Tables A frequency table is helpful to visualize the spread of data. Create a frequency table for the data Which measure of central tendency is best representative of the center of the data? Salary Tally Frequency Mean: $30.7𝑘 or $30,700 Median: $15.5𝑘 or $15,500 Mode: $15 𝑘 or $15,000

In Class Practice U7D1 – ICP

Must Do (3/24): Which of the following CANNOT change the value of a median in a set of five numbers?   (A) Adding 0 to the set (B) Multiplying each value by -1 (C) Increasing the least value only (D) Increasing the greatest value only (E) Squaring each value 2. {2, 3, 9, 4, 11, 4x – 8, 3y – 4} The modes of the set above are 2 and 11. What is one possible value of x + y? 4x – 8 = 2 and 3y – 4 = 11 4x – 8 = 11 and 3y – 4 = 2 Let’s deal with possibility 1 first: 4x – 8 = 2 4x = 10 x = 2.5 3y – 4 = 11 3y = 15 y = 5 So one possible value of x + y is 2.5 + 5 = 7.5. d