HELP ASAP
1 answer:
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You know 1 is not a root because the sum of the coeffcients of the equation is 14, not zero.
It is fairly easy to try 3 by synthetic division (see attachment), which tells you that 3 is a root and the remaining quadratic factor is x²-3x-5. The quadratic formula tells you the roots of that factor are
... x = (-b±√(b²-4ac))/(2a) = (3±√29)/2
The appropriate choices are
... C. (3-√29)/2
... D. (3+√29)/2
... F. 3
_____
The quadratic formula tells you the solution to
... ax²+bx+c=0
is x = (-b±√(b²-4ac))/(2a)
We have a=1, b=-3, c=-5.
Answer:
a: 0.9544 9 within 8 units)
b: 0.9940
Step-by-step explanation:
We have µ = 300 and σ = 40. The sample size, n = 100.
For the sample to be within 8 units of the population mean, we would have sample values of 292 and 308, so we want to find:
P(292 < x < 308).
We need to find the z-scores that correspond to these values using the given data. See attached photo 1 for the calculation of these scores.
We have P(292 < x < 308) = 0.9544
Next we want the probability of the sample mean to be within 11 units of the population mean, so we want the values from 289 to 311. We want to find
P(289 < x < 311)
We need to find the z-scores that correspond to these values. See photo 2 for the calculation of these scores.
We have P(289 < x < 311) = 0.9940
