HW6_skeleton

7.2

• 1. standard normal distribution
• 2. 1-Za
• 3. .309
• 4. .421
• 1. area=.0071

  2. area=.334

  3. area=.912

  4. area=.9998

• 1. area=.999

  2. area=.944

  3. area=.038

  4. area=.0009

• 15. Z-score= .67
• 17. Z-scores= -2.58, 2.58
• 18. Z-scores= -1.88; 1.88
• 23. =.9839

shadenorm(mu=50, sig=7, above = 35,col = "blue",dens = 150)

• 24. =.0162

shadenorm(mu=50, sig=7, above = 65,col = "blue",dens = 150)

• 25. =.2375

shadenorm(mu=50, sig=7, below = 45,col = "blue",dens = 150)

• 1. Pr=.8657

  2. Pr=.0132

  3. Proportion=.7019

  4. Proportion=.1230

  5. P=.9649=96th percentile

  6. P=.0359=4th Percentile

8.1

• 1. sampling distribution.
• 2. M; SigmaX=Sigma/sqrt n
• 3. standard error; mean
• 4. True.
• 5. False.
• 6. False.
• 7. shape=Normal center=30 spread=2.53
• 8. The population is greater than 30, therefore the Central limit theorem says that it will be Normal regardless. Tge sampling distribution=.632
• 9. M=80; Sigma=2
• 10. M=64; Sigma=3
• 1. Shape=Normal by cental limit theorem Center=80 Spread=2

  2. 6.68%

  3. 1.79%

  4. 79.69%

• 1. 35.2% of the pregnancies would last less than 260 days.

  2. 3.578

  3. 4.65

  4. .40%

  5. Maybe the sample was biased and not random or it was sampled outside of the population.

  6. 98.45%