From a population with mean 1056, a sample of 400 with sample mean 910 is taken. Then value of test statistic is (σ = 400):
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → -7.3
$z = \frac{\bar{x} - \mu}{\sigma/\sqrt{n}}$
$= \frac{910 - 1056}{400/\sqrt{400}}$
$= \frac{-146}{400/20}$
$= \frac{-146}{20}$
$= -7.3$
The value of test statistic is $-7.3$.