Question

Ten randomly selected groceries in the city has an average sales of 2890000 from various goods with a standard deviation of 260000 is this enough evidence to conlcude that groceries are less than the average of php 3090000 from various goods months at a=0.05 using pvalue approach

Answer 1

3090000-2890000=PHP200000. This is 200000/260000=0.77 standard deviations below the mean. This corresponds to a p-value of about 0.22. A significance level of 0.05 is much lower than this, so the p-value is higher than the critical value and therefore within the range in which the null hypothesis (that is, the average value of sales is still PHP3090000) is not to be rejected, and we can't conclude that the average is less than PHP3090000.