Find the standard test statistic t for a sample with n 12 x2

Find the standard test statistic t for a sample with n= 12, x=20.4, and s=2.1, if H1:u=20.9 (put strike through = sign)

a. -.008

b.-.381

c.-.037

d.-.825

Solution

Test Statistic
Population Mean(U)=20.9
Sample X(Mean)=20.4
Standard Deviation(S.D)=2.1
Number (n)=12
we use Test Statistic (t) = x-U/(s.d/Sqrt(n))
to =20.4-20.9/(2.1/Sqrt(12))
to =-0.825

[ANSWER] d.-.825