Answer:
2.576
Step-by-step explanation:
Given :
Confidence level (α) = 99%
Z(1 - α)/2 = Z(1 - 99%)/2
Z1%/2 = Z1%/ 2
Z0.5% = Z0.005
Z(0.99 + 0.005) = Z0.995
Using the Z distribution table ; locate the z value for the proportion 0.995 ; this corresponds to approximately 2.57
Similarly, using the Invnorm calculator function :
Invnorm(0.995) gives a Zscore of :
2.576
