<span>solution:
we have, mean =8.4 hrs, std. deviation = 1.8 hrs, sample size n = 40 , X = 8.9
Probability(X<8.9) = ?
we know that, Z = (X - mean)/(std. deviation/(sqrt. n)) = (8.9 - 8.4)/(1.8/(sqrt.40))
Z = 1.7568
from standard normal probabilities table, we have , P(Z<1.7568) = 0.9608
Hence, probability that the mean rebuild time is less than 8.9 hours is 0.9608</span>
Answer:
<em>(2·4)² = 64 / (6*2)² = 144</em>
Step-by-step explanation:
Follow PEMDAS :
Parenthesis first, so:
2 * 4
==> 8
Then Exponent:
8 ^2
==> 64
(2·4)² = 64
Do the same for (6:2)² :
Parenthesis first :
6 * 2
==> 12
Then Exponent:
12^2
==> 144
(6:2)² = 144