In: Statistics and Probability
The average cost of a traffic fine is $600 this year. It's claimed that the amount has increased. Data collected from a simple random sample of 86 people that have been fined since January, showed that the mean amount was $720. With a standard deviation of $31.75, is there enough evidence to support the claim?
a) state null and alternative hypothesis and state the claim
b) Find the standardized test statistic. Show complete formula
c) Calculate p-value. Is the null hypothesis rejected? Why?
d) Interpret the decision.