Warm UP! The top five salaries and bottom five salaries at Technology Incorporated are shown in the table below. a)Find the mean absolute deviation for each set of data. Round to the nearest hundredth. b) Compare the variations of the data sets. 7.46, 2.14

EOCT Practice #1 A science teacher recorded the pulse rates for each of the students in her classes after the students had climbed a set of stairs. She displayed the results, by class, using the box plots shown. Which class had the highest pulse rate after climbing the stairs? 3

EOCT Practice #2 A teacher determined the median scores and interquartile ranges of scores for a test she gave to two classes. In Class 1, the median score was 70 points, and the interquartile range was 15 points. In Class 2, the median score was 75 points, and the interquartile range was 12 points. Which range of numbers includes only third quartile of scores for both classes? a)70 to 87 points b)70 to 85 points c)75 to 87 points d)75 to 85 points D

Comparing Data

Welcome to MHS CSI! O ver the weekend, a student entered the school grounds without permission. Even though it appears that the culprit was just looking for a quiet place to study undisturbed by friends, school administrators are anxious to identify the offender and have asked for our help. The only available evidence is a suspicious footprint outside the library door. A fter the incident, school administrators arranged for data to be obtained from a random sample of our students. The following table shows the shoe print length (in cm), height (in inches), and gender for each individual in the sample.

This collection of data is considered an observational study and not an experiment. Why? The schools administrators chose to collect data on a random sample of students from the school. Explain what benefits a random sample offers. Which type of graph (Histogram, Dot Plot, Box Plot) would you suggest be used to compare the shoe print length data distributions for females and males? Why? For YOUR gender calculate the five-number summary for the shoe print lengths. Then determine if there are any outlying shoe print length values. Share your summary with a member of the opposite gender. Construct a parallel box plot to compare the data sets.

Shoe Print Length Gender Shoe Print LengthGender 24F 24.5F 32M 22.5F 27F 29M 26F 24.5F 25.5F 25F 30M 37M 31M 27F 29.5M 32.5M 29F 27F 25F 27.5F F 25F 25.5F 31M 27F 32M 31M 27.4F 26F 30M 27F 25F 28F 26.5F F 30F 22.5F 31F 27.25F Find the mean of the male and female shoe print lengths. If the length of a students shoe print was 32 would you think that the print was made by a male or a female? What if the suspects shoe print length was 27 cm?

Comparing Distributions Old Faithful, a geyser in Yellowstone National park, is renowned for erupting fairly regularly. In more recent times, it has become less predictable. It was observed that the time interval between eruptions was related to the duration of the most recent eruption. The distribution of its interval times for 2011 is shown below. a)Does the distribution seem normal, skewed, or uniform? b)What does the distribution tell you about the time between eruptions?

Measures of Center: Mode A unimodal distribution is data set with one mode. A bimodal distribution is one with two modes, usually at some distance apart from each other. A uniform distribution is one in which all values occur with the same frequency (no mode/all modes). A normal distribution is a unimodal one that is bell shaped with a peak in the middle.

Measures of Dispersion Visually When traveling to these two cities, would the same clothing be suitable for both cities at any time during the year from the point of view of warmth?

Measures of Shape The skewness is a measure of the shape of a distribution. It can be left skewed, right skewed or not skewed at all. It is always the opposite of what you think!

How the Shape of the Distribution Affects the Mean and Median For a severely right skewed distribution, in general, the mean is greater than the median. For a severely left skewed distribution, in general, the mean is less than the median. For a symmetric distribution, the mean equals the median.

Which Measure of Central Tendency Should One Use An article in the Wall Street Journal online ( 112.html) from August 24, 2007 reported the following: 112.html The average cost of a wedding is between $27,400 and $28,800. The median is approximately $15,000. How can we justify this apparent contradiction in the cost of a wedding?

Class Work Finish the worksheet. We will talk about your answers at the end of class

Homework Read the 2 way frequency chart notes and practice problems. We will be working with these frequencies in class Monday so YOU MUST HAVE READ THE NOTES AND ATTEMPTED THE PRACTICE PROBLEMS. NO EXCUSES!