Assume the sample populations do not have equal standard deviations and use the .05 significance level:

(a) Determine the number of degrees of freedom and round down to the nearest integer value

(b) State the decision rule

(c) Compute the value of the test statistic

(d) State your decision about the null hypothesis

A recent survey compared the costs of adoption through public and private agencies. For a sample of 16 adoptions through a public agency, the mean cost was $21,045, with a standard deviation of $835. For a sample of 18 adoptions through a private agency, the mean cost was $22,840, with a standard deviation of $1,545.