Question

BusSchool admin receives a memo from their head office which claims that 5% of all registration documents throughout the organisation have had to be returned because of incorrect or missing information.   BusSchool admin checks their last 60 registration documents and finds that 6 of these were returned because of incorrect or missing information.

1. Construct a point estimate of the proportion of all BusSchool registration documents that are returned because of incorrect or missing information.
2. Use a hypothesis test (5% significance level) to determine whether the proportion of returned registration documents for BusSchool admin is significantly worse than what the head office has claimed to be true for the whole organisation.   In particular:
   1. State your null and alternative hypothesis
   2. Provide an appropriate test statistic accurate to four decimal places
   3. State the critical value accurate to two decimal places
   4. State whether you accept or reject your null hypothesis
   5. Make a conclusion about the proportion of BusSchool registration documents that are returned because of incorrect or missing information.
3. In this context, describe what a Type II error would be?

Criticise the sampling method that BusSchool used: speculate on the biases that they could have incurred and propose a better method

Answer 1