Business Statistics

Chapter 9 | Statistical Inference: Estimation for Single Populations 285

lie on the right side of the normal curve is

(0.5000 –

2



) = (0.5000 – 0.005) = 0.4950.

Similarly, the area where population mean is

likely to lie on the left side of the normal curve is

(0.5000 –

2



) = (0.5000 – 0.005) = 0.4950.

This area is associated with a z value of 2.575

(from Table 9.2). While dealing with es-

timation, a simple question might strike a

researcher. Why can’t we select the highest

condence and always use that level? In or-

der to answer this question, we need to un-

derstand the tradeoff between sample size, interval width, and the level ...