The answer is B (3, 9), (1,-5), (3,3)
Answer:
68%
Step-by-step explanation:
Given that:
Mean speed (m) = 46
Standard deviation (s) = 13
Approximately what percentage of vehicle speeds were between 33 and 59 mph
Obtain the Zscore for P(Z < x) for both values and subtract :
For x = 33
Zscore :
Z = (x - m) / s
Z = (33 - 46) / 13 = - 1
p(Z < - 1) = 0.15866 ( Z probability calculator)
For x = 59
Zscore :
Z = (x - m) / s
Z = (59 - 46) / 13 = 1
p(Z < 1) = 0.84134 ( Z probability calculator)
Hence, 0.84134 - 0.15866 = 0.68268 = 0.68
0.68 * 100% = 68%
