In 1998, the Department of Agriculture estimated that a typical U.S. family of four would spend $157 per week for food. A random sample of 8 Kansas families of four that year yielded the following weekly food costs:

143

169

149

135

138

152

150

141

Does the data provide sufficient evidence at the .10 level of significance to conclude that in 1998 the mean weekly food cost for Kansas families of four was less than the national mean of $157? Suppose it is known that the population is not normally distributed, but it is a safe assumption that the population is symmetric