Laughter among deaf signers. Refer to the Journal of Deaf Studies and Deaf Education (Fall 2006) paired difference study on vocalized laughter among deaf users of sign language, presented in Exercise 9.44 (p. 490). Suppose you want to estimate md = 1mS - mA2, the difference between the population mean number of laugh episodes of deaf speakers and deaf audience members, using a 90%

confidence interval with a sampling error of .75. Find the number of pairs of deaf people required to obtain such an estimate, assuming that the variance of the paired differences is s2 LO5 d = 3.