1 Is the random variable x discrete or continuous Choose the

1. Is the random variable x discrete or continuous? Choose the correct answer below.

a) Continuous

b) Discrete

2. Use the standard normal table to find the z-score that corresponds to the cumulative area 0.9898 . If not in the table, use the entry closest to the area. If the area is halfway between two entries, use the z-score halfway between the corresponding z-score.

Z=

Solution

1)

Random variable X is may be discrete or continuous

2)

we have to find Z score

with area 0.9898

let score is \"W\"

so

P(-W<Z<W )=0.9898

so

P(-W<Z<W)=P(Z<W) - P(Z<-W)=P(Z<W) - (1-P(Z<)=2P(Z<W) - 1=0.9898

so

2P(Z<W)=1.9898

then

P(Z<W)=1.9898/2

            =0.9949

then from standerd normal distribution table

W=2.57

hence Z score=2.57