Question

A sample of 20 fish are captured in lake A and their concentrations of polychlorinated
biphenyl are measured using a certain technique. Furthermore, 15 fish are captured
in lake B and and their concentrations of polychlorinated biphenyl are measured. The
data (in parts per million) are summarized as follows:

mean standard deviation sample size Lake A Lake B 12.42 12.50 1.167 1.141 20 15 Boxplots are constructed for each lake: 15 14 13 polychlorinated biphenyl (ppm) 12 11 Lake A Lake B Is it reasonable to assume that A. the populations are normal with equal variances B. the populations are normal with unequal variances C. only one of the populations is normal D. the populations are not normal E. none of the preceding

Answer 1

From provide information and boxplot of lake 1 and lake 2

For lake 1 data distributed symmetrical at center medium ,therefore lake 1 is normal

For lake 2 data is not distributed symmetrical.it right skewed ,lake 2 is not normal.

Q : Is reasonable to assume that ,

Answer : C. Only one of the population is normal.

Thank You!