15. Temperature transducers of a certain type are shipped in batches of 50. A sample of 60 batches was selected, and the number of transducers in each batch not conforming to design speci cations was determined, resulting in the following data:

2 1 2 4 0 1 3 2 0 5 3 3 1 3 2 4 7 0 2 3 0 4 2 1 3 1 1 3 4 1 2 3 2 2 8 4 5 1 3 1 5 0 2 3 2 1 0 6 4 2 1 6 0 3 3 3 6 1 2 3

a. Determine frequencies and relative frequencies for the observed values of x  number of nonconforming transducers in a batch.

b. What proportion of batches in the sample have at most ve nonconforming transducers? What proportion have fewer than ve? What proportion have at least ve nonconforming units?

c. Draw a histogram of the data using relative frequency on the vertical scale, and comment on its features.