HW5_skeleton
First Name Last Name
February 28, 2017
7.1
31.
shadenorm(mu = 62, sig = 18, below = 44, col = "blue", dens = 200)
Interpretation 1. Type answer here.
15.87% of cell phone plans in the U.S. charge less than 44$.
Interpretation 2. Type answer here.
The probability of choosing a cell phone plan that charges less than 44$ is 15.87%.
32.
shadenorm(mu = 14, sig = 2.5, above = 17, col = "blue", dens = 200)
Interpretation 1. Type answer here.
11.51% of refrigerators have lives longer than 17 years.
Interpretation 2. Type answer here.
The probability of selecting a refrigerator last longer than 17 years is 11.51%
33.
shadenorm(mu = 3400, sig = 505, above = 4410, col = "blue", dens=200)
Interpretation 1. Type answer here.
2.28% of birth weights of full-term babies are larger than 4410 grams.
Interpretation 2.Type answer here.
The probability of selecting a full-term baby who is heavier than 4410 grams is 2.28%
34.
shadenorm(mu = 55.9, sig = 5.7, below = 46.5, col = "blue", dens=200)
Interpretation 1. Type answer here.
4.96% of 10-year-old males are shorter than 46.5 inches.
Interpretation 2. Type answer here.
The probability of selecting a 10-year-old who is shorter than 46.5 inches is 4.96%
35.
Interpretation 1. Type answer here.
19.08% of human pregnancies are longer than 280 days.
Interpretation 2. Type answer here.
The probability of selecting a woman who has pregnancy longer than 280 days is 19.08%
Interpretation 1.Type answer here.
34.16% of human pregnancies are between 230 and 260 days.
Interpretation 2. Type answer here.
The probability of selecting a woman who has pregnancy between 230 and 260 days is 34.16%
36.
Interpretation 1. Type answer here.
33.09% of experiments result in more than 26 miles per gallon.
Interpretation 2. Type answer here.
The probability of selecting an experiment that results in more than 26 miles per gallon is 33.09%
Interpretation 1. Type answer here.
11.07% of experiments result in 18-20 miles per gallon.
Interpretation 2. Type answer here.
The probability of selecting an experiment that result in 18-20 miles per gallon is 11.07%
7.2
5.
- Type answer here.
0.0071
- Type answer here.
0.3336
- Type answer here.
0.0885
- Type answer here.
0.9998
7.
- Type answer here.
1-0.0013=0.9987
- Type answer here.
1-0.0559=0.9441
- Type answer here.
1-0.9625=0.0375
- Type answer here.
1-0.9995=0.0005
9.
- Type answer here.
0.9793-0.0207=0.9586
- Type answer here.
0.5000-0.2912=0.2088
- Type answer here.
0.9971-0.1492=0.8479
11.
- Type answer here.
0.0228*2=0.2508
- Type answer here.
0.0594+(1-0.9948)=0.0646
- Type answer here.
0.4052+(1-0.8849)=0.5203
13. Type answer here.
z=-1.28
15. Type answer here.
1-0.25=0.75 z=0.67
17. Type answer here.
-2.5<z<2.5
33. Type answer here.
z=-1.35 x=50-1.35*7=40.44
35. Type answer here.
z=0.87 x=50+0.877=56.09 37.*
shadenorm(mu = 21, sig = 1.0, below = -1000, col = "blue", dens=200)
- Type answer here.
z=(20-21)/1=1 pr(x<20)=50%-68%/2=16%
- Type answer here.
z=(22-20)/1=2 pr(x>22)=50%-95%/2=2.5%
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when x=19, z=(19-20)/1=-1 pr(19
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pr(x<1125)=pr(z<-1.16)=0.1230
- Type answer here.
z=(1475-1262)/118=1.81 area to the left=0.9649 96th percentile
- Type answer here.
z=(1050-1262)/118=-1.80 area to the left=0.0359 4th percentile
41.
- Type answer here.
proportion of x>270 = pr(z>0.25)=1-0.5987=0.4013=40.13%
- Type answer here.
proportion of x<250=pr(z<-1)=0.1587=15.87%
- Type answer here.
proportion of 240<x<280=pr(-1.625<z<0.875)=0.8106-0.0516=0.759=75.9%
- Type answer here.
pr(x>280)=pr(z>0.875)=1-0.8106=0.1894
- Type answer here.
pr(x<245)=pr(z<-1.31)=0.0951
- Type answer here.
pr(x<224)=pr(z<-2.625)=0.0043 Very preterm babies are unusual.
43.
- Type answer here.
proportion of x<24.9=pr(z<-1.43)=0.0764=7.64%
- Type answer here.
proportion of discarded rods = pr(x<24.85)+pr(x>25.15) =pr(z<-2.14) + pr(z>2.14)=0.0324=3.24%
- Type answer here.
5000*3.24%=162
- Type answer here.
proportion of 24.9<x<25.1= pr(-1.43<z<1.43)=1-0.0764*2=0.8472 10000/0.8472=11803.59 The plant manager should manufactre 11804 steel rods.