Help with Statistics

Hello!  Can someone please help with the following questions?

1)  Serum ferritin is used in diagnosing iron deficiency. In a study conducted recently researchers discovered that in a sample of 28 elderly men the sample standard deviation of serum ferritin was 52.6 mg/L. For 26 younger men the sample standard deviation was 84.2 mg/L. At the .01 level of significance, do these data support the conclusion that the ferritin distribution in elderly men has a smaller variance than in younger men?

A.Yes, because the test value 2.56 is greater than the critical value 0.394   
 B.Yes, because the test value 2.56 is greater than the critical value of 2.54   
 C.Yes, because the test value 0.390 is less than the critical value 2.54   
 D.No, because the test value 1.60 is less than the critical value of 2.54

2)  Two teams of workers assemble automobile engines at a manufacturing plant in Michigan. A random sample of 145 assemblies from team 1 shows 15 unacceptable assemblies. A similar random sample of 125 assemblies from team 2 shows 8 unacceptable assemblies. Is there sufficient evidence to conclude, at the 10% significance level, that the two teams differ  with respect to their proportions of unacceptable assemblies?

 A.No, since the test value exceeds the critical value   
 B.Yes, since the p-value is greater than 0.10   
 C.No, since the test value does not exceed the critical value   
 D.No, since the p-value is less than 0.10

3) The marketing manager of a large supermarket chain would like to determine the effect of shelf space (in feet) on the weekly sales of international food (in hundreds of dollars). A random
sample of 12 equal –sized stores is selected, with the following results:

Store      Shelf Space(X)   Weekly Sales(Y)
1      0         2.0
2      10         2.6
3      10         1.8
4      15         2.3
5      15         2.8
6      15         3.0
7      20         2.7
8      20         3.1
9      20         3.2
10      25         3.0
11      25         3.3
12      25         3.5

Find the equation of the regression line for these data. What is the value of the coefficient of
determination?  Place your answer, rounded to 3 decimal places, in the blank.  Do not use a dollar sign.  For example, 0.345 would be a legitimate entry.   

4)  Are America's top chief executive officers (CEOs) really worth all that money? One way to answer this question is to look at the annual company percentage increase in revenue versus the CEO's annual percentage salary increase in that same company. Suppose that a random sample of companies yielded the following data:

percent change for corporation   15   12   3   12   28   6   8   2
percent change for CEO      6   17   -4   12   32   -1   7   2


Do these data indicate that the population mean percentage increase in corporate revenue is
greater than the population mean percentage increase in CEO salary? Use a 5% level of
significance. What is the p-value associated with this test of hypothesis? Place your answer,
rounded to 3 decimal places, in the blank. For example, 0.134 would be a legitimate entry.