In a Mathematics test, there are 10 multiple choice questions 2 marks will be awarded for each correct answer, while 1 mark will be deducted for each wrong answer. If Peter answers all the questions in the test and his test result is 8 marks, how many correct answers has he got in the test? (Algebraic Equations in One unknown)

A. find the power of the test, when the null hypothesis assumes a population mean of mu = 450, with a population standard deviation of 156, the sample size is 5 and the true mean is 638.47 with confidence intervals of 95 b. find the power of the test, when the null hypothesis assumes a population mean of mu = 644, with a population standard deviation of 174, the sample size is 3 and the true mean is 744.04 with confidence intervals of 95% c. find the power of the test, when the null hypothesis assumes a population mean of mu = 510, with a population standard deviation of 126, the sample size is 10 and the true mean is 529.44 with confidence intervals of 95