i got b and c wrong, could you help with those?

The mean SAT score in mathematics, , is 578. The standard deviation of these scores is 30. A special preparation course claims that its graduates will score higher, on average, than the mean score 578. A random sample of 60 students completed the course, and their mean SAT score in mathematics was 389. At the 0.05 level of significance, can we conclude that the preparation course does what it claims? Assume that the standard deviation of the scores of course graduates is also 30. Perform a one-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places, and round your responses as specified below. (If necessary, consult a list of formulas.) (a) State the null hypothesis Ho and the alternative hypothesis H. O P Ho : u = 578 X S H : H > 578 (b) Determine the type of test statistic to use. Chi-square Degrees of freedom: 59 0=0 030 020 (c) Find the value of the test statistic. (Round to three or more decimal places.) 040 00 -2.840 X 5 (d) Find the critical value. (Round to three or more decimal places.) 1.645 (e) Can we support the preparation course's claim that its graduates score higher in SAT? OYes ONo