I dont know where to beging with this one.
To start with, they give us the population mean = 4.5. Then when calculating the variance of the data, we should measure that variance vs the population mean, rather than the sample mean.
The worst part is that they then calculate the t statistic using the standard error of the mean!!? We were asked about the probability of an event occuring on the first day of next week. For this we need to think about the distribution of daily data. We do not need to think about the distribution of the sample mean.
I sincerely hope that GARP do not mark us down for their errors on the actual exam.