Very novice question re calculating Wald test

[Russell Bourne]

I know that the Wald test uses 'test' as command but I have some simple calculations to make on approximate Wald test , note no data frame.
So how do you solve Wald test on

: H0 : gamma=1, vs H1: gamma not= 1 where gamma=p1/p2

Observed

n1=78, n2 = 51, Sum of xi=207, sum of yj=212

therefore observed p1= n1/sum xi = 78/212

observed p2= n2/sum yj = 51/202

observed gamma = p1/p2 = 78/207 * 202/51

Covariance matrix 2x2 = I(p2,gamma)^-1 = [ 0.000862 -0.00561]
.................................................. .................. [ -0.00561 0.056136]

Thanks for any input and hope I am clear with question.

[Carlo Lazzaro]

Russell:
welcome to this forum.
I think the best approach is skimming through the Methods and formulas section and related reference in -test- entry, Stata .pdf manual.
See also:
https://stats.idre.ucla.edu/stata/fa...test-in-stata/
https://www.statalist.org/forums/for...1208-wald-test