x = number of hours
want to find probability (P) x >= 13
x is N(14,1) transform to N(0,1) using z = (x - mean) / standard deviation so can look up probability using standard normal probability table.
P(x >= 13) = P( z > (13 - 14)/1) = P(z > -1) = 1 - P(z < -1) = 1 - 0.1587 = 0.8413
To convert that to percentage, multiply 100, to get 84.13%
-4x^4 - 15x^2 + 1 - 19/x^2 is your answer
Hope I helped :)
Answer:
2%
Step-by-step explanation:
Set up a proportion
x / 100 = 12 / 600
Cross multiply
600x = 1200
Divide both sides by 600
x = 2
I hope this helped and please mark me as brainliest!
Logically you can see that since 26 is half way between 24&28 it is 1/2 sd.
See sketch