Let X e a random variable with mean mu=100 and standard deviation sigma=10. Determine the proportion of values of X that fall within the following intervals.
a) (90, 110)
Please explain your answer so I can learn this material...thanks
2007-07-19 09:26:02 · 3 answers · asked by C K 3 in Science & Mathematics ➔ Mathematics
This question is asked twice, one using the empirical rule and one with out it....I need to know how to calculate this without using the mound distribution graph.
2007-07-19 09:33:39 · update #1
Use the empirical rule:
P(90 < x < 110)
= P(mu - 10 < x < mu + 10)
= P(-1 < z < 1)
= 0.68
The answer is 68%
2007-07-19 09:31:14 · answer #1 · answered by whitesox09 7 · 0⤊ 0⤋
If you assume a normal distribution, then Z1 = (90-100)/10 = -1.0
and Z2 = (110- 100)/10 and Φ[1] - Φ[-1] = 0.8413 - 0.1587 =0.6826 or 68.26%
2007-07-19 19:34:31 · answer #2 · answered by cvandy2 6 · 0⤊ 0⤋
This is one sigma to each side. Approximately 68%.
2007-07-19 16:34:09 · answer #3 · answered by gebobs 6 · 0⤊ 0⤋