a random sample of 100 credit sales in a department store showed an average sale of 130.00. from past data it is known that the standard deviation of the population is 30.00. (round answer to two decimal places)

a) determine the standard error (in dollars) of the mean

b) with a 0.95 probability determine the margin of error (in dollars)

c) what is the 95% confidence interval of the population mean (in dollars)? $____to $____

You may naed to use the appropriaten append ox tabhe or technotogy to anwaer this question. (Hound your ansivers to two decimal places.) (a) Determine the stundard mrner (in dolars) of the mean. (b) With =0.95 probability, determine the margin of error (in dolars). (c). What is the essh confidence intarval of the pogulabion meaf (in doltarsy? to 5