Question

uiz Instructions Question 2 3 pts A sample data set with a bell-shaped distribution has mean2 and standard deviation s 1.1. Find the approximate proportion of observations in the data set that lie: 1. below -0.2; [Select 2. below 3.1; I Select ] 3. between -1.3 and 0.9. [ Select ] Previous Next

Answer 1

1)

for normal distribution z score =(X-μ)/σx
here mean=       μ=	2
std deviation   =σ=	1.1000

probability =

P(X<-0.2)

=

P(Z<-2)=

0.0228

2)

probability =

P(X<3.1)

=

P(Z<1)=

0.8413

3)

probability =

P(-1.3<X<0.9)

=

P(-3<Z<-1)=

0.1587-0.0013=

0.1574