Answer:
72 hours
Step-by-step explanation:
Rate =Distance / Time
Rate=400/18=22.222
Time=Distance/ Rate
Time= (1600 x 18)/400 = 72hours
the probability is P=0.012 (1.2%)
for the random variable X= weight of checked-in luggage, then if X is approximately normal . then the random variable X₂ = weight of N checked-in luggage = ∑ Xi , distributes normally according to the central limit theorem.
Its expected value will be:
μ₂ = ∑ E(Xi) = N*E(Xi) = 121 seats * 68 lbs/seat = 8228 lbs
for N= 121 seats and E(Xi) = 68 lbs/person* 1 person/seat = 68 lbs/seat
the variance will be
σ₂² = ∑ σ² (Xi)= N*σ²(Xi) → σ₂ = σ *√N = 11 lbs/seat *√121 seats = 121 Lbs
then the standard random variable Z
Z= (X₂- μ₂)/σ₂ =
Zlimit= (8500 Lbs - 8228 lbs)/121 Lbs = 2.248
P(Z > 2.248) = 1- P(Z ≤ 2.248) = 1 - 0.988 = 0.012
P(Z > 2.248)= 0.012
then the probability that on a randomly selected full flight, the checked-in luggage capacity will be exceeded is P(Z > 2.248)= 0.012 (1.2%)
B. 2/5
First we write down the numbers.
1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20.
Multiplies of three or five above are: 6,9,10,12,15,16,19,20 (there are 8)
So 8/20.
8/20 simplified is 2/5
So, it's B.
