1. A marketing study found that the mean spending in 15 categories of consumer items for 297 respondents in the 18-34 age group was $71.86 with a standard deviation of $70.90. For 736 respondents in the 35+ age group, the mean and standard deviation were $61.53 and $45.29, respectively. Test the hypothesis that there is no di erence in the mean spending between these two groups.