+0  
 
0
76
2
avatar

Use the normal distribution of fish lengths for which the mean is

10

inches and the standard deviation is

4

inches. Assume the variable x is normally distributed.

(a)

What percent of the fish are longer than

11

​inches?

(b)

If

400

fish are randomly​ selected, about how many would you expect to be shorter than

8

​inches?

 Mar 23, 2020
 #1
avatar+111330 
+1

(a)   longer than 11 inches

 

[ 11 - 10]

________  =      1/4  = .25

      4

 

The  percentage associaed with this z score  is   .5987

 

So approx   1 - .5987  =  .4013  ≈  40.13%   fish are longer than 11 inches

 

 

(b)  shorter than 8 inches

 

[ 8 - 10]

_______  = -1/2  = -.50

      4

 

The percentage associated with this z score is  .3085

 

So.....the   number of  fish  out of 400  that  are shorter than 8 inches =

 

400 (.3085)  ≈   123  

 

 

cool cool cool

 Mar 23, 2020
 #2
avatar+1970 
+1

Nice, Chris!!!

CalTheGreat  Mar 23, 2020

8 Online Users

avatar
avatar