Answer
The null hypothesis is rejected and this means that these results indicate that the average expenditure has changed.
Work Step by Step
Given that, $\mu=10337, \sigma=1560, n=150, \bar x =10798$, then,
$H_{0}:\mu=10337.\\ H_{1}:\mu \ne10337.$
Let $\alpha=0.05$, then, $Z_{0.025}=1.96$, the critical region is $R-(-1.96,+1.96)$.
$Z=\frac{\bar x- \mu}{\frac{\sigma}{\sqrt{n}}}=\frac{10798- 10337}{\frac{1650}{\sqrt{150}}}\approx 3.42$
Since Z=3.42 lies in the critical region, the null hypothesis is rejected.
