thickness of insulation

A random sample was taken of the thickness of insulation in transformer windings, and the following thicknesses (in millimeters) were recorded:

a) Make a stem-and-leaf display for these data. Show at least five stems. Sort the data on each stem in order of increasing magnitude.

b) Estimate from these data the percentage of all the windings that received more than 30 mm of insulation but less than 50 mm.

c) Find the median, lower quartile, and ninth decile of these data.

d) Make a frequency table for the data. Use Sturges’ rule.

e) Draw a frequency histogram.

f) Add and label an axis for relative frequency.

g) Draw a cumulative frequency graph.

h) Find the mode.

i) Show a box plot of these data.