Her estimate is lower than her actual cost because her total is 72.87 she is off by 1.72 because she only added 42,17,and 12 and forgot all about adding the cent or the .60,.38,and the .89.
Answer:
0.9544
Step-by-step explanation:
P(-2 < Z < 2) means that Z has mean 0 and standard deviation 2.
P(−2 < Z < 2) = F(2) - F(-2)
Using the Z - table,
F(2) = 0.9772
and F(-2) = 0.0228
Thus,
P(−2 < Z < 2) = 0.9772 - 0.0228 = 0.9544
This means that data within two standard deviation is 95%.