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Question 1155440: The weights for newborn babies is approximately normally distributed with a mean of 6 pounds and a standard deviation of 1.4 pounds.
Consider a group of 1000 newborn babies:
1. How many would you expect to weigh between 4 and 9 pounds?
2. How many would you expect to weigh less than 7 pounds?
3. How many would you expect to weigh more than 6 pounds?
4. How many would you expect to weigh between 6 and 10 pounds?
Answer by dkppathak(439)   (Show Source):
You can put this solution on YOUR website! The weights for newborn babies is approximately normally distributed with a mean of 6 pounds and a standard deviation of 1.4 pounds.
Consider a group of 1000 newborn babies:
1. How many would you expect to weigh between 4 and 9 pounds?
2. How many would you expect to weigh less than 7 pounds?
3. How many would you expect to weigh more than 6 pounds?
4. How many would you expect to weigh between 6 and 10 pounds?
solution
1 mean=6 sd=1.4 total number 1000 find number weight between 4 to 9 pounds
z=x-mue/sd
4-6/1.4=-2/1.4 =-1.42 z value by table 0.0793
z=9-6/1.4=3/1.4=2.14 z value by table 0.9904
effective value 0.9904-0.0793 =0.9111
number of children =1000x0.9111=911,1
911 children
2. less than 7 pounds
z=7-6/1.4=1/1.=0.71
number of children born less than 7 pounds =0.7611x1000=761.1
means 761 children less than 7 pounds
3.more than 6 pounds
z=6-6/1.4=0/1.4=0 z>0 z value as per table 0.5
number of children born 1000x0.5=500
number of children born more than 6 pounds are 500
z<0.71 z value by table 0.7611
4. weight between 6 to 10 pounds
z=6-6/1.4=0/1.4 =0 value of z by table 0.5
z=10-6/1.4=4/1.4 =2.85 value of z by table 0.9977
0
value will be 0.9977-0.5000=0.4977
number of children born between 6 to 10 pounds =0.4977x1000=497.7 means 498
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