Answer:
(x+2) (x+3) (x-5)
Step-by-step explanation:
x³-19x-30 = (x+2) (x²+ax-15) ... x³=x*(1*x²) while -30= (2)*(-15)
x³ +<u> 0</u>*x² - 19x -30 = x³ + (<u>2+a</u>)x² + (2a-15)x -30
2+a = 0
a = -2
x³-19x-30 = (x+2) (x²-2x-15) = (x+2) (x+3) (x-5)
Step-by-step answer:
standard deviation (sigma) = 12 inches
mean (mu) = 90 inches.
For 36 years, the standard error of the mean is
e = sigma / sqrt(n) = 12" / sqrt(36) = 2".
Deviation from the mean
= 92.8 -90 = 2.8
Since the standard error of the mean follows the normal distribution, we have
Z=(92.8-90)/2 = 1.4
Looking up the normal distribution tables, or check R, we find
P(Z>1.4) = 1-P(Z<1.4) = 1-0.9192433 = 0.08075666
Answer: P(snowfall>92.8) = 0.0808 (to four decimal places)
