Seeing is believing!

Before you order, simply sign up for a free user account and in seconds you'll be experiencing the best in CFA exam preparation.

Basic Question 1 of 10

A consumer group wants to prove that average hospital costs are more than $931 per day. The group randomly samples 60 accounts and finds a sample mean of $950. The hypothesis test is at an α-level of 5% and assumes a σ of $50. The critical value is ______ standard deviations.

A. 1.645
B. -1.645
C. 1.28

User Contributed Comments 7

User Comment
Bibhu One can refer to www.mathsnet.net/asa2/modules/s33binom.html for further reading on this subject. The easier way is sample mean 950 above 931. So +Z and then 5% means 1.645.
whiteknight we can approach the problem like this...for 5% level of significance in a one tail test the z value is 1.645...i.e the right hand portion of the normal distribution....thus for any Z greater than 1.645 this statement will hold true ...
raymondg could somebodyplease explain how to arrive to 1.645 ?
meghanchloe I THOUGHT 5% LEVEL OF SIGNIFICANT IS 1.96
ebayer 5% one tail = 10% both tails -> use 1.645 instead of 1.96.
johntan1979 This test is clearly one-tailed (>931). So answer should be 1.645 if alpha is .05. two-tailed would be 1.96.
Sp1993 Hi johntan1979, could you please clarify why a two-tailed test would give an answer of 1.96! Thanks!
You need to log in first to add your comment.
Your review questions and global ranking system were so helpful.
Lina

Lina

Learning Outcome Statements

explain hypothesis testing and its components, including statistical significance, Type I and Type II errors, and the power of a test

CFA® 2025 Level I Curriculum, Volume 1, Module 8.