Question

The standard normal curve shown below models the population distribution of a random variable. What proportion of the values in the population does not lie between the two z-scores indicated on the diagram?

http://media.apexlearning.com/Images/200712/20/394c2d3e-12bc-4812-be69-bb30bb5205f9.gif

Answer 1

@amistre64

Answer 2

access denied ....

Answer 3

sorry! It is a standard z curve, left z score= -1.2, and the right z score= .85. @amistre64

Answer 4

The proportion lying to the left of z = -1.2 can be found from a standard normal distribution table.. Can you do this step?

Answer 5

@topoftheworld24 Are you there?

Answer 6

this is table
http://en.wikipedia.org/wiki/Standard_normal_table#Cumulative_table

Answer 7

Also
P(Z>z) = 1- P(Z<z)
assuming z is positive
P(Z<-z) = 1-P(Z<z)

Answer 8

The table here has negative values of z:
http://lilt.ilstu.edu/dasacke/eco148/ztable.htm

Answer 9

i got the table but i didnt know what to do after

Answer 10

If you are using this table, http://lilt.ilstu.edu/dasacke/eco148/ztable.htm , what value do you get when you look in the column headed '.00' to the right of the z value -1.2 ?

Answer 11

@topoftheworld24 How are you going with the table?

Answer 12

.1151

Answer 13

Good work! Now find the probability value for z = 0.85 (lets call it p). Then the proportion of values to the right of z = 0.85 (call it p1) is given by:
p1 = 1 - p.
Finally the required proportion of values is:
0.1151 + p1