Question

**A z-value**

Multiple Choice

is the standard deviation for the standard normal probability distribution

is a measure of how many standard deviations the mean is from the median

is the difference of the mean and the probability of z

is a measure of how many standard deviations an observation is from the mean

Answer #1

Solution :

A z-value **is a measure of how many standard deviations
an observation is from the mean .**

P( - 1< X < + 1) = 68%

P( - 2< X < + 2) = 95%

P( - 3< X < + 3) = 99.7%

In a standard normal distribution, the probability that Z is
less than zero is
Multiple Choice
-0.5
0.0
0.5
1.0
For the standard normal probability distribution, the total area
under the curve is
Multiple Choice
0.0
0.5
1.0
3.0
The random variable x is known to be uniformly distributed
between 50 and 100. The probability of x having a value between 70
to 95 is
Multiple Choice
.25
.50
.75
1.00
x is a normally distributed random variable with a...

Table 1: Cumulative distribution function of the standard Normal
distribution
z: 0 1 2 3 Probability to the left of z: .5000 .84134 .97725 .99865
Probability to the right of z: .5000 .15866 .02275 .00135
Probability between z and z: .6827 .9544 .99730
Table 2: Inverse of the cumulative distribution function of the
standard Normal distribution
Probability to the left of z: . 5000 .92 .95 .975 .9990 z: 0.00
1.405 1.645 1.960 3.09
1 Normal Distributions
1. What proportion...

How is the
t-distribution similar to the standard normal
z-distribution?
Multiple Choice
Both are skewed
distributions.
Both are continuous
distributions.
Both are discrete
distributions.
Both are families of
distributions.

1. True or False.
1a. z-scores follow a standard normal distribution.
1b. A z-score indicates how many standard deviations a value is
1b. above or below the mean.
1c. Point estimators are always good estimates of population
parameters, and there are never any deviations or errors
1d. The process of converting a value x from a normal
distribution to a z-score is known as standardization

1. What is the probability that a value chosen from the
standard normal distribution is less than -0.67? (Keep 4
decimals)
2. What is the probability that a value chosen from the
standard normal distribution is greater than 1.8? (Keep 4
decimals)
3. what is the probability that a value chosen from the
standard normal distribution is between 0.57 and 1.35? (Keep 4
decimals)
4. Find Q1 for the standard normal distribution. (Keep 2
decimals)
5. Find Q3 for the...

A: Let z be a random variable with a standard normal
distribution. Find the indicated probability. (Round your answer to
four decimal places.)
P(z ≤ 1.11) =
B: Let z be a random variable with a standard normal
distribution. Find the indicated probability. (Round your answer to
four decimal places.)
P(z ≥ −1.24) =
C: Let z be a random variable with a standard normal
distribution. Find the indicated probability. (Round your answer to
four decimal places.)
P(−1.78 ≤ z...

Q1. Suppose that Z has a standard normal distribution (with mean
0 and a standard deviation of 1, as in Table E.2). a. What is the
probability that:
i) Z is less than 1.45
ii) Z is greater than 1.55
iii) Z is between 1.45 and 1.55
b. What is the value of Z if only 10% of all possible Z values
are larger?

Consider an arbitrary, continuous normal distribution with a
given mean and standard deviation. Derive an integral function that
gives the percentile of a particular value, X. The integration is
analytical, yet it is often given a functional representation
erf(). Look it up and plot the erf function in terms of the mean
and standard deviation. Estimate the 25th and 75th percentile.
Within how many standard deviations from the mean is 50% of the
distribution?

In a standard normal distribution, find the probability P(z >
1.02).
In a standard normal distribution, find the probability P(z <
-.35).

For a standard normal distribution, find: P(-1.73 < z <
-0.77)
For a standard normal distribution, find: P(z > c) = 0.9494
Find c.
Assume that z-scores are normally distributed with a mean of 0
and a standard deviation of 1.
If P(z>c)=0.2789 P(z>c)=0.2789 , find c
Assume that z-scores are normally distributed with a mean of 0
and a standard deviation of 1. If P(z>d)=0.7887 P(z>d)=0.7887
, find d.
Assume that z-scores are normally distributed with a mean of...

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 7 minutes ago

asked 19 minutes ago

asked 20 minutes ago

asked 20 minutes ago

asked 24 minutes ago

asked 27 minutes ago

asked 37 minutes ago

asked 39 minutes ago

asked 40 minutes ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago