Experimental Designs Answers

When the students select their random samples and plot the results on a dotplot, which of the following should they expect to see?The dots, which represent the sample proportions obtained by the students,

The manager of the marbles store wants to increase the precision of the estimate of the true mean dollar amount of all purchases made by customers at his store that day.Which sample size will give the manager the greatest precision of the estimate of the true mean dollar amount of all purchases made by customers at his store that day?

When are the results of an experiment said to be statistically significant?