Question

assume the random variable x is normally distributed with mean 80 and standard deviation 4. Find the indicated Probability P (70<×<76)

Answer #1

Solution:

We are given that the random variable X is normally distributed.

Mean = 80

SD = 4

We have to find P(70<X<76)

P(70<X<76) = P(X<76) – P(X<70)

First find P(X<76)

Z = (X – mean) / SD

Z = (76 – 80)/4 = -4/4 = -1

P(Z<-1) = 0.158655

(by using z-table or excel)

P(X<76) = 0.158655

Now find P(X<70)

Z = (70 – 80) / 4

Z = -2.5

P(Z<-2.5) = 0.00621

(by using z-table or excel)

P(X<70) = 0.00621

P(70<X<76) = P(X<76) – P(X<70)

P(70<X<76) = 0.158655 - 0.00621

P(70<X<76) = 0.152445

Required probability = 0.152445

Assume the random variable x is normally distributed with mean
u=90 and standard deviation o=4. Find the indicated probability.
P(77<x<86)

Assume that the random variable X is normally distributed, with
mean 80 and standard deviation 15 Compute the probability P(X >
79).

assume the random variable X is normally distributed with a mean 80
in standard deviation 9.4
find the P (x>72)
find the P (95<x<105)
find x so that the area above x is .80

1.Assume the random variable x is normally distributed with mean
mu=83 and standard deviation sigma=5. Find the indicated
probability. P(X<76)
2. Find the indicated z-score shown in the graph to the right.
Area= 0.7357
3.find the critical value tc for the confidence level c=0.99 and
sample size n=7.

A random variable is normally distributed with a mean of
80 and a standard deviation of 6.
a) Find P(X < 75.5)
b) Find P(X > 82)
c) Find P(77 < X < 84.8)

1. Assume the random variable x is normally distributed with
mean μ=85 and standard deviation σ=5. P(69 < x <83)
Find the indicated probability.

Assume that the random variable X is normally distributed, with
mean μ = 80 and standard deviation σ = 10. Compute the probability
P(95 < X <100).
Answers:
a) 0.1093
b) 0.0823
c) 0.0441
d) 0.0606

Assume that the random variable X is normally distributed, with
mean =59 and standard deviation of 10 compute the probability
P(56<X ≤ 68)

assume that the random variable x is normally distributed, with
mean=90 and standard deviation=12. compute the probability
p(57<x<107).

assume the random variable X is normally distributed with mean
u=50 and standard deviation of 7. What is the probability of
P(X>35) and draw the curve.

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 11 minutes ago

asked 22 minutes ago

asked 25 minutes ago

asked 33 minutes ago

asked 37 minutes ago

asked 55 minutes ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago