Question

A sample containing years to maturity and yield for 40 corporate bonds are contained in the data given below.

Years to Maturity		Yield		Years to Maturity		Yield
23.50		4.757		3.75		2.769
21.75		2.473		12.00		6.293
21.50		4.464		17.50		7.411
23.50		4.684		18.00		3.558
27.00		4.799		8.25		0.945
18.25		3.755		23.25		2.966
15.75		7.068		14.75		1.476
2.00		7.043		10.00		1.382
8.75		6.540		23.00		6.334
5.25		7.000		15.25		0.887
11.25		4.823		4.75		4.810
25.75		1.874		18.00		1.238
14.25		5.654		3.00		6.767
19.25		1.745		9.50		3.745
25.00		8.153		17.50		4.186
6.75		6.571		17.00		5.991
23.00		7.506		9.50		7.322
19.00		2.857		5.50		4.871
10.75		8.010		27.50		2.403
21.25		4.214		26.00		4.500

a. What is the sample mean years to maturity for corporate bonds and what is the sample standard deviation?

Mean	？ (to 4 decimals)
Standard deviation	？ (to 4 decimals)

b. Develop a 95% confidence interval for the population mean years to maturity. Round the answer to four decimal places.

（ , ） years

c. What is the sample mean yield on corporate bonds and what is the sample standard deviation?

Mean	？(to 4 decimals)
Standard deviation	？(to 4 decimals)

d. Develop a 95% confidence interval for the population mean yield on corporate bonds. Round the answer to four decimal places.

（ , ）percent

Answer 1

Answer a)

Mean and standard deviation for years to maturity for corporate bonds has been calculated using MS Excel:

Mean	15.6875
Standard deviation	7.4678

Answer b)

A 95% confidence interval for the population mean years to maturity is (13.2988,18.0762) years

Answer c)

Mean and standard deviation for yield on corporate bonds has been calculated using MS Excel:

Mean	4.5961
Standard deviation	2.1648

Answer d)

A 95% confidence interval for the population mean yield on corporate bonds (3.9037, 5.2885) percent