Consider the following hypothesis test:-
$H_0: μ = 20$
$Η_a: μ ≠20$
A sample of 40 provided a sample mean of 19. The standard deviation is 3. Then the value of the t-test statistic is:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → -2.1 **
Given:
$H_0:\mu=20$
Sample mean $\bar{x}=19$
Sample size $n=40$
Standard deviation $s=3$
Test statistic:
$\displaystyle t=\frac{\bar{x}-\mu_0}{s/\sqrt{n}}$
Substitute:
$t=\frac{19-20}{3/\sqrt{40}}$
$t=\frac{-1}{0.4743}\approx -2.108$
t ≈ -2.11