Sony expects their phone batteries to have a life of at least 18 hours Sony expects their phone batteries to have a life of at least 18 hours. They check 41 phone batteries and see the average battery life to be 17.1 hours. The standard deviation of these batteries are 3.2 hours. Check for a confidence level of 90% whether they are having their expectations met.

Pepsodent hires you as a quality consultant Pepsodent hires you as a quality consultant. They are concerned that whether their middle sized toothpaste tube is having exactly 192 g of toothpaste or not. To check this, you take a sample of 130 toothpaste packets and find that they have on average 189 g of toothpaste in them. The production manager tells you that the machines are designed in such a way that all the tubes have a fluctuation of 1.7 g. Given these details, and for a significance of 5%, what do you tell Pepsodent?

Sanofi is interested to know whether the blood pressure drug that they recently came up with is outperforming the market or not. At present, they expect an average drug for blood pressure to reduce the pressure by 12 units at most. They give the drug to 18 patients and see that the pressure reduction is by 12.3 with a standard deviation 2.5 units. For a confidence level 95%, do you think Sanofi’s new drug is outperforming the others?