An old medical textbook states that the mean sodium level for healthy adults is 139 mEq per liter of blood. A medical researcher believes that, because of modern dietary habits, the mean sodium level for healthy adults, J, now differs from that given in the textbook. A random sample of 80 healthy adults is evaluated. The mean sodium level for the sample is 138 mEq per liter of blood. It is known that the population standard deviation of adult sodium levels is 10 mEq. Can we conclude, at the 0.10 level of significance, that the population mean adult sodium level differs from that given in the textbook? Perform a two-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. p Ho : 0 X S H, :0 (b) Determine the type of test statistic to use. (Choose one) 0=0 OSO 020(c) Find the value of the test statistic. (Round to three or more decimal places.) (d) Find the two critical values. (Round to three or more decimal places.) I and (e) Can we conclude that the population mean adult sodium level differs from that given in the textbook? O Yes O No