PPT-Standard Deviation & Z-Scores

Lets start with an example I divided the class into 2 teams A and B Coincidentally the quiz average for team A is the same as team B 815 So we expect a graph of their scores to be about the same right. DESCRIPTION The formula for the standard deviation is EQ 221 while the formula for the weighted standard deviation is EQ 222 where w is the weight for the ith observation N is the number of nonzero weights and is the weighted mean of the observation Normal distributions show up all over the place.. The standard normal distribution. The standard normal distribution is a . continuous distribution.. It has a mean of 0 and a standard deviation of 1. TIPS FOR APLIA. Developed By: . Ethan Cooper (Lead Tutor) . John Lohman. Michael Mattocks. Aubrey Urwick. Chapter 4: . Variability. Key Terms: Don’t Forget . Notecards. Variability (p. 104). Range (p. 106). The standard deviation as a ruler. The men’s combined skiing event in the winter Olympics consists of two races: a downhill and a slalom. Times for the two events are added together and the skier with the lowest total time wins. In the 2006 Winter Olympics, the mean slalom time was 94.2714 seconds with a standard deviation of 5.2844 seconds. The mean downhill time was 101.807 seconds with a standard deviation of 1.8356 seconds. Ted . Standard Deviation. . summarizes . the amount . each value . deviates. from . the mean. . . SD. . tells us how . spread out . the data items are in our data set.. If data . is close together, . standard will . Comparing two different results. You can do this with your tests. How well did you go?. Tim wants to know if . is hard study has paid . off. . He recently completed two math tests.. This is what I told him. Objectives:. To calculate and interpret the standard deviation of a data set. To compare the standard deviation of data sets. Warm-up: Complete Problem 1, Questions 1 – 5, on pages 490 – 491.. Use. Variability. Di . Fara. Gino’s. Di . Fara. 1. 2. 4. 3. 4. 4. 3. 4. 1. 3. 3. 2. 5. 3. 2. Gino’s. 2. 3. 2. 3. 2. 2. 4. 4. 4. 3. 2. 4. 3. 2. 4. Σ 44 Σ 44. /15 . /. 15. Intro to Statistics. What is Normal Distribution?. Modeled by a Bell-shaped curve.. Symmetric about the mean.. Mean (average) and the Median (middle #) are the same number. Or at least very close!!. Can look tall and skinny, short and wide or somewhere in the middle. . Room 315. Gas mileage samples for 250 new Honda Fit are normally distributed, with a mean of 31.3 mpg and a standard deviation of 3.6 mpg. a. Determine the percent of samples that are between 27.7 mpg and 38.5 mpg. 1. 0. In addition to level 3.0 and above and beyond what was taught in class,  the student may:. · Make connection with other concepts in math. · Make connection with other content areas.. The student will summarize, represent, and interpret data on a single count or measurement variable.. Since the averages are the same, can we assume that the students in both classes all did pretty much the same on the exam?. The answer is… No.. The average (mean) does not tell us anything about the distribution or variation in the grades.. MLA annual meeting, Orlando, Florida. February 24, 2017. Matt Ertz, University of Louisville. matthew.ertz@louisville.edu. Background. Scores of . Scores. Background. Began to appear around 2009. Many score channels decimated by copyright infringement. Find the standard deviation and variance of a set of values. . Apply standard deviation and variance. . Vocabulary. Standard deviation: A measure of how far the numbers in a data set deviate from the mean. Represented by the Greek letter Sigma .