In the solution for problem Chapter 8 30 part B how do you

In the solution for problem Chapter 8, 30 - part B, how do you calculate that Z score of 2.776, - what numbers do they correspond with on the table? When I calculated it - I came up with 2.78 - which gives a slightly different final answer, but in accordance with our textbook table - perhaps I am not looking the z score up correctly or calculating it correctly. Please help

Solution

The z score corresponding to 2.776 or 2.78 is: 0.9973.

The above z score is found from the table.