A bank recently offered to the market two highly competitive, fixed rate savings bonds, namely a taxable bond and a tax-free cash ISA. Both bonds required a minimum investment of £25,000 and were only available to investors who provided new funds to the bank. Following the launch of these bonds, the Customer Services department of the bank began to receive a significant number of complaints from potential investors in both types of bond regarding the incorrect processing of their applications.
As part of its investigation into this problem, the bank initially wished to investigate whether
the error rate in processing applications differed between the two bond types. A random
sample of 400 previously processed applications was taken for each bond type, and each
was carefully checked for errors