(a) The voltage labelled on a certain type of battery is 1.5 volts. A random sample of 50 batteries is selected and its mean is 1.53 volts. Assuming that the voltage of the batteries is normally...

Extracted text: (a) The voltage labelled on a certain type of battery is 1.5 volts. A random sample of 50 batteries is selected and its mean is 1.53 volts. Assuming that the voltage of the batteries is normally distributed with standard deviation 0.112 volts, test, at 1% significance level, whether the mean voltage of the batteries has not changed. i. State the null hypothesis and alternative hypothesis to be tested. ii. Conduct a statistical test on the hypotheses. i1. State your conclusion. (b) State three (3) graphs that are suitable to represent quantitative data.