The 68-95-99.7 rule tells us 68% of the probability is between -1 standard deviation and +1 standard deviation from the mean. So we expect 75% corresponds to slightly more than 1 standard deviation.
Usually the unit normal tables don't report the area between -σ and σ but instead a cumulative probability, the area between -∞ and σ. 75% corresponds to 37.5% in each half so a cumulative probability of 50%+37.5%=87.5%. We look that up in the normal table and get σ=1.15.
So we expect 75% of normally distributed data to fall within μ-1.15σ and μ+1.15σ
That's 288.6 - 1.15(21.2) to 288.6 + 1.15(21.2)
Answer: 264.22 to 312.98
Answer:
0.003 but if you just put that in backwards, 345.
Step-by-step explanation:
Simple you just solve for y and put the equation in slope-intercept form
m^2 -11m -60 = 0
m^2 -11m =60
(m^2 -11m + 121/4) = 361/4
(m - 11/2)^2 = 361/4
m - 11/2 = + or - 19/2
m = 11/2 + 19/2, 11/2 - 19/2
m = 15, -4
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m^2 -11m -60
(11 +- Square root (121 +240))/2
11/2 +- 19/2
m= 15, -4
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m^2 -11m -60
(m - 15) (m + 4)
m = 15, -4
