A Test Was Made Of $H _ { 0 } : \mu _ { 1 } = \mu _ { 2 }$

Multiple Choice

A test was made of $H _ { 0 } : \mu _ { 1 } = \mu _ { 2 }$ versus $H _ { 1 } : \mu _ { 1 } < \mu _ { 2 }$ . The sample means were $\bar { x } _ { 1 } = 13$ and $\bar { x } _ { 2 } = 12$ , the sample standard deviations were $s _ { 1 } = 4$ and $s _ { 2 } = 3$ , and the sample sizes were $n _ { 1 } = 16$ and $n _ { 2 } = 15$ .
How many degrees of freedom are there for the test statistic?

A) 15
B) 16
C) 11
D) 14