Answer:
1) Critical value[tex]Z_{\alpha /2} = 2.58[/tex]
2) 622.0036
Explanation:
Given data:
confident interval is 99%
population mean is 3 units
standard deviation 29
[tex]\alpha = 1 - 0.99 = 0.01[/tex]
[tex]\alpha = 0.01[/tex]
Critical value[tex]Z_{\alpha /2} = 2.58[/tex]
From standard table of Z
b)
Minimum sample size [tex]= (Z_{\alpha /2} \times \sigma / E)^2[/tex]
[tex]= (2.58 \times (29 / 3))^2[/tex]
= 622.0036
= 623 (Rounded up to next integer)