Hi All:
OK here is the promised info for the exam on Monday. Remember, it was about the pennies in the foam cup demonstration. We don't have graphics yet so I'll give you the questions and the answers to go with them.
Write these answers down in your Blue Formula Sheet notes and bring them with you to the exam.
a) Why do the points not lay perfectly on the line? (because the values of stretch were rounded to the nearest 0.5 cm)
b)What is the dependent variable and what does it represent? (the dependent variable is 'S' and it represents the amount of stretch)
c) What is the meaning of the point (40, 31)? (it means that when 40 pennies are in the cup the elastic stretched 31 cm.)
d) Draw a line of best fit and determine the slope of the line. (Draw a line exactly between the points
(0, 26) and (100, 39). The slope of the line is 13/100 which is exactly 0.13.)
e) What type of variation is it? (It is a partial variation.)
f) Give a formula for this relationship. (S = 0.13n + 26)