Il. Students are given a standardized test in the 7h grade and once again in the
ID: 3330159 • Letter: I
Question
Il. Students are given a standardized test in the 7h grade and once again in the 12" grade. Each student has a s scores (x.y) where x is the score in the 7h grade and y is the score in the 12h grade. The x values have a mean standard deviation 46 and the y values have a mean of 566 and standard deviation 77. The correlation coefficient gressing y on x is r = 0.86. The regression equation is y-1 54 x + 188 Predict the 12th grade score from a student with 7"grade score of 250 10) What percent of the variation in 12h grade scores is explained by the regression equation? 11) The following are reasons to AVOID using a regression line for prediction, except for which one? B) 215 C) 573 D) 502 E) 493 A) 385 A) 95% A) r is close to 0 B) the x-value used for prediction is far from the data x-values. C)x and y units are not t B) 86% C) 74% D)100% E) 93% D) the scatter-plot shows a curved pattern E) the data were badly sampled. IV. ResenrchnExplanation / Answer
properties of correlation
1. If r = 1 Corrlation is called Perfect Positive Corrlelation
2. If r = -1 Correlation is called Perfect Negative Correlation
3. If r = 0 Correlation is called Zero Correlation
& with above we conclude that correlation ( r ) is = 0.86< 0, positive correlation
a.
regression equation is Y'= 1.54 x + 188
when 7th grade score of 250 is => y' = 1.54 * 250 + 188 = 573
b.
value of correlation is = 0.86
coeffcient of determination = r^2 =0.7396 ~ 74%
for part c, option c is not fully readible. I could give the one which can't be answer
Option A,Option E, Option D are can't be answer