In a study of store checkout scanners, 1234 items were checked and 20 of them were found to be overcharges. Use a 0.05 level of significance to test the claim that with scanners, 1% of sales are overcharges. (Before scanners were used, the overcharge rate was estimated to be about 1%) Based on these results, do scanners appear to actually increase occurrences of overcharges?
Test the given claim, and draw the appropriate graph. Use the traditional method or the P-value method of testing hypotheses (or your instructor may specify which method to use with assigned exercises). Assume that all samples have been randomly selected.