A hole-punch machine is set to punch a hole 1.894 cm in diameter. It is important that the hole is exactly 1.84 cm. To measure the accuracy of the machines, a random sample of 12 punched holes and their diameters were measured. (Use 90% confidence). Mean of the sample is 1.8475 and s = 0.021. 

Use both critical value and p-value approach.