Question

3. The following is a table of the ages, in months, (x) of 7 infants and the number of hours (y) each slept in a day. x months 1.5 2.0 7.0 5 4 .5 6 Ly hrs. 15 14.5 13.5 13.0 14.0 11.5 | 12.5 (a) Make a scatter diagram and draw the line you think best fits the data. (b) Does line you drew, indicate a positive or negative correlation, between an infant's age in months and the number of hours of sleep? (c) Use the calculator to compute the value of r. (d) Does this value of r correlate with your answer in part (b)? Explain in at least one sentence,

Answer 1

(a) The scatter diagram is as shown below: scatterplot hrs 10 months (6) There exists a negative correlation between an infants age in months and number of hours of sleep

(c) The calculation of the r in Excel is as shown below: B9 X f =CORREL(A2:A8,B2:38) A B C D E F 1 months hrs 1.5 15 2 14.5 13.5 13 14 6 11.5 12.5 -0.75 9 The value ofr is -0.75. (d) Yes, because there is a negative sign with the value ofr. Good luck with your studies!!!