Need explanation and six step hypothesis test answers

Although it is generally accepted to leave a tip of 15% at a restaurant it is believed by the manager of a local restaurant that the average tip left at their restaurant is 20%. A random sample of 20 checks is selected from a local restaurant to see if this belief is true. This sample has a mean of 19.4% and a standard deviation of 2.75%.

Use the p-value approach and the sample statistics to test the managers claim. Use a significance level of 0.10. Show all 6 steps of the hypothesis test.