The relationship between hospital patient-to- nurse ratio and various characteristics of job satisfaction and patient care has been the focus of a number of re- search studies. Suppose x 5 patient-to-nurse ratio is the
680 -.75
690 1.2
700 -.3
720 .25
740 .3
740 1.5
750 1.1
750 2.0
760 1.1
780 1.1
790 2.0
810 2.1
815 2.8
820 2.2
825 .9
835 2.35
840 2.3
845 2.2
a. Construct a scatterplot for these data.
b. What is the value of the correlation coef?cient?
c. Find the equation of the least-squares line.
d. Predict the volume of cerebral grey matter at age 2 to 5 years for a child whose head circumference z score at age 12 months was 1.8.
e. Explain why it would not be a good idea to use the least-squares line to predict the volume of grey matter for a child whose head circumference z score was 3.0.