The owner of a lawn care company is concerned about the amount of time one of her employees, Michael, needs in order to complete lawn fertilization service. The reason for her concern is that slow service times result in selling service packages to fewer customers, and therefore lower profits. The target time to fertilize a standard size lawn (1000 m2) is 5 minutes. The owner selects a random sample of 10 fertilization services provided by Michael and records the time it takes for him to complete each service. The times, in minutes, are as follows:
7 10 4 5 6 7 5 3 7 2.
Is there sufficient evidence to suggest that, on average, Michael exceeds the target service time? Use the p-value method toconduct an appropriate hypothesis test at the 10% level of significance. What must you assume is true in order for your conclusion to be valid?