MATH 109 Lecture Notes - Lecture 11: Scatter Plot
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Covert x to sux: 2. ) multiply sux with pie to get suy, 3. ) knowing the suy find y. Y=mean of y +(suy)(sdy: 1. ) (18-16. 65)/1. 7=0. 79, 2. ) Alternative method: this example can also be doen by finding the equation of the regression line y=mx+b, where. We can also predict value for x using the values for y: x=average x +(1/r)(y-average y/sdy)sdx. In a certain class, midterm scores average out to 60 with an sd of 15, as do scores on the final. The correlation b/t midterm scores and final scores is about 0. 5. Estimate the average final score for the students whose midterm scores was 30: midterm average:60= average x, midterm sd:15=sd of x, final average:60=average of y, final sd:15=sd of y, correlation coefficient:0. 5=r, 1. ) A university has made a statistical analysis of the relationship b/t math sat scores and first- year gpas, for students who complete the first year. The results: average sat score=550, sd=80, average first-year gpa=2. 6, sd=0. 6, r=0. 4.
