Answer:
Bobby around 131 minutes and Billy around 111 minutes
Step-by-step explanation:
To solve the problem it is important to raise equations regarding what happens.
They tell us that Billy (Bi) and Bobby (Bo) can mow the lawn in 60 minutes. That is to say that what they prune in a minute is giving as follows:
1 / Bo + 1 / Bi = 1/60 (1)
They say Billy could mow the lawn only in 20 minutes less than it would take Bobby, therefore
1 / Bi = 1 / (Bo-20) (2)
Replacing (2) in (1) we have:
1 / Bo + 1 / (Bo-20) = 1/60
Resolving
(Bo - 20 + B0) / (Bo * (Bo-20) = 1/60
120 * Bo - 1200 = Bo ^ 2 - 20Bo
Rearranging:
Bo ^ 2 - 140Bo -1200 = 0
Now applying the general equation
Bo = 130.82 or Bo = 9.17, <em>this last value cannot be because Billy took 20 minutes less and neither can he prune faster than the two together</em>, therefore Bobby only takes around 131 minutes and Billy around 111 minutes
Checking with equation 1:
1/131 +1/111 = ~ 1/60
You subtract 15.50 from 47.50
then you will get your answer it is 31
Answer:
Same in both sets
Minimum , medium
Different
IQR
Cannot tell
mode, mean
Step-by-step explanation:
Answer:
X ~ N(27, 4) ;
xbar ~ N(27, 0.1026) ;
0.5 ;
0.5
Step-by-step explanation:
Probability distribution of X : N(μ, σ²)
μ = 27 ; σ = 2
X ~ N(μ, σ²) = X ~ N(27, 2²) ;X ~ N(27, 4)
Distribution is approximately normal ; μ = xbar ; xbar = 27
(Standard Error)² = (σ/√n)²= (2/√39)² = 0.1026
xbar ~ N(μ, σ²) = xbar ~ N(27, 2²) ; xbar ~ N(27, 0.1026)
Probability that a randomly selected individual found a job in less than 27 weeks :
P(X < 27) :
Obtain the Zscore :
Z = (x - μ) / σ
Z = (27 - 27) / 2 = 0/2
Z = 0
P(Z < 0) = 0.5
D.) n = 36
P(X < 27) :
Obtain the Zscore :
Z = (x - μ) / σ/√n
Z = (27 - 27) / (2/√36) = 0/0.33333
Z = 0
P(Z < 0) = 0.5
