Answer:
0.5640
Step-by-step explanation:
n = 12 (number of adults)
p = 0.65 (probability that an adult is satisfied with the job the major airlines were doing.
x = number of adults out of 11 who were satisfied.
a)
P( x = 5) = 11C5 (0.65)^5 (0.35)^6 = 0.0986
b)
P( x < 3) = P(x=0)+P(x=1)+P(x=2)
P( x =0) = 11C0 (0.65)^0 (0.35)^11 = 0.0000
P( x =1) = 11C1 (0.65)^1 (0.35)^10 = 0.0002
P( x =2) = 11C2 (0.65)^2 (0.35)^9 = 0.0018
Add: P( x < 3) = 0.0020
c)
P( x ≥ 8) = P(x=8)+P(x=9)+P(x=10)+P(x=11)
P( x =8) = 11C8 (0.65)^8 (0.35)^3 = 0.2254
P( x =9) = 11C9 (0.65)^9 (0.35)^2 = 0.1395
P( x =10) = 11C10 (0.65)^10 (0.35)^1 = 0.0518
P( x =11) = 11C11 (0.65)^11 (0.35)^0 = 0.0087
add:
P( x ≥ 8) = 0.4254
d)
P(x=4)+P(x=5)+P(x=6)+P(x=7)
P( x =4) = 11C4 (0.65)^4 (0.35)^7 = 0.0379
P( x =5) = 11C5 (0.65)^5 (0.35)^6 = 0.0985
P( x =6) = 11C6 (0.65)^6 (0.35)^5 = 0.1830
P( x =7) = 11C7 (0.65)^7 (0.35)^4 = 0.2428
Add: 0.5640
