a) Z = -1.82 ≠ 1.82 Km/L
Otherwise it is correct.
b) Z = .92 (not km/L)
Don't need to subtract from one (which is correct of the two), if you use column for proportion in smaller area in the table.
Final answer correct.
Can someone help me verify if this is correct?
Gasoline usage for compact cars in Canada is a normal distribution with a mean of 33.3 km/l and with standard deviation of 7.3 km/L. Round your answers to one decimal place.
a) What percentage of compact cars obtains 20km/L or LESS?
z= x-mean/standard deviation
= 20-33.3/7.3
= 1.82 Km/L
(find percent through z-score table)
which becomes 0.0344 x 100
= 3.4 %
b) What percentage of compact cars obtains MORE than 40 km/L
z=40-33.3/7.3
= 0.92 km/L = 0.8212
= 1 - 0.8212
= 0.1788 x 100
= 17.9%
Question is, for question b, is it 1-0.8212 or 100-0.8212?
1 answer