An ambulance service claims that the proportion, p, of calls received that involve life-threatening emergencies is greater than 50%. Can we support this claim at the 0.05 level of significance, if 77 calls out of a random sample of 130 calls selected from the service's files involved life-threatening emergencies? Perform a one-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places and round your answers as specified in the table. (If necessary, consult a list of formulas.) (a) State the null hypothesis H, and the alternative hypothesis H. O P Ho : 0 X S p H, : 0 (b) Determine the type of test statistic to use. Degrees of freedom: 0=0 030 020 (c) Find the value of the test statistic. (Round to three or more decimal places.) 0*0 00 0 X 5 ? (d) Find the critical value. (Round to three or more decimal places.) 0 (e) Can we support the claim that the proportion of calls received that involve life-threatening emergencies is greater than 50%? Yes ONo