I was looking at the step by step solution for Ch 6 36 in Es

I was looking at the step by step solution for Ch. 6 #36 in \"Essentials of Modern Business Statistics with Microsoft Office Excel 5e\".

On 36a I was not able to figure out how the z value was 1.645 because when I look up the z value for 0.05 the cloest one is 1.64. How can you carry it out to three decimal places?

On 36b I was not able to figure out how the 4000 z value for -0.716 as .2358 instead of .2389 and how the 6000 z value for -0.0966 as .4622 instead of .4641.

Please help me with this if possible.

Thank you

Solution

I donot have the book copy but I can definitely help out to determine the Z value

36a Can be determined sing tables or from excel. If the Z value are calculated from excel it can be calculated to 3 decimal places.

=NORMSINV(0.05)

36b

Following link can be used for table value

https://www.stat.tamu.edu/~lzhou/stat302/standardnormaltable.pdf

From the table it can be seen

-0.71   -----    0.23885

0.72 ------ 0.23576

Actually when it is 0.2358 considered means 0.71 is considered and ignored the Z score calulated for the third digit.

Actually more appropriate method is to find iterpolated value of Z score.