Question

A distribution of scores has a mean of LaTeX: \muμ= 80. If your score is X = 72, which standard deviation would give you a better grade: LaTeX: \sigmaσ= 4 or LaTeX: \sigmaσ= 6? If your score is X = 90, which standard deviation would give you a better grade: LaTeX: \sigmaσ= 5 or LaTeX: \sigmaσ= 10?

Answer #1

**A standard deviation of scores has a mean of 80. The
score is X=72.**

**Now, if sigma is 4, then the grade is the z-score
is**

**=(72-80)/4**

**=-8/4**

**=-2**

**Now, if sigma=6, then the grade is the z-score
is**

**=(72-80)/6**

**=-8/6**

**=-1.33**

**So, as the z-score -1.33 is more than the z-score -2,
then the sigma=6 will give a better score for X=72.**

**Now, if the score is X=90.**

**Then, sigma=5 will give a grade or z-score
of**

**=(90-80)/5**

**=2**

**And, the z-score of sigma=10 is**

**=(90-80)/10**

**=1**

**So, as the z-score of 2 is more than the z-score of 1,
so sigma=5 will give a better grade.**

For a population with a mean of LaTeX: \muμ= 100 and a standard
deviation of LaTeX: \sigmaσ=20, Find the X values that corresponds
to each of the following z-scores: z = -.40 z = -.50 z= +1.80 z =
+.75 z = +1.50

1. Suppose an x distribution has mean LaTeX: \muμ= 10 and a
standard deviation of 2. Random sample sizes of 25 are drawn.
Describe the x-bar (mean of the sample) distribution and mean
and standard deviation of the distribution.
Find the z-values and the probability that x-bar will be between
9.8 and 10.6.

The length of a human pregnancy is approximately normally
distributed with mean LaTeX: \muμ=266 days and standard deviation
LaTeX: \sigmaσ=16 days. Given the values of LaTeX: \muμx-bar and
LaTeX: \sigmaσx-bar found in the preceding questions, find the
probability that a random sample of 36 pregnancies has a mean
gestation period of 260 days or less. In other words, find P(x-bar
LaTeX: \le≤ 260). Choose the best answer. Group of answer choices
.0122 .0274 .3520 .0465

Suppose your score on an exam is 76 and the exam scores are
normally distributed with a mean of 70. Which is better for you: A
distribution with a small standard deviation or a large standard
deviation? Explain.

A distribution of scores has a mean of ?=100 and a standard
deviation of ?=10. For an x value of 140, calculate the
corresponding z-score.Can you also interpret what the z-score of x
means (x=140)?

1.The distribution of 2015 SAT scores in mathematics are
normally distributed with a mean score of 514 points and a standard
deviation of 118 points. What score does a student need in order to
score in the top 1% of all SAT scores?
ANSWER QUESTIONS A-G FOR QUESTION ABOVE(DRAW LABEL NORMAL
CURVE)
(A) label the x-axis with a complete description in the context
of the setting on Normal curve.
(B) label the value of the mean
(C) label the value...

3. A population of scores has µ = 44. In this
population, a score of X = 40 corresponds to z = –0.50.
What is the population standard deviation?
a.
2
b.
4
c.
8
d.
-8
4. Last week Tim got a score of X = 54 on a math exam
with µ = 60 and σ = 8. He also got X =
49 on an English exam with µ = 55 and σ = 3, and
he...

Test scores on an exam follow a normal
distribution with mean = 72 and standard deviation =
9. For a randomly selected student, find
a)
P(x ≥ 80), b) P(65 <x<90), what is thed minimum svore to be
among top 12 percent

A population of scores has a mean of 44. In this population a
score of X= 40 corresponds to z = -0.50. What is the population
standard deviation?

A normal distribution of MA-321 test scores has a mean of 81.7
and a standard deviation of 5.8 Answer the following: a) What
percentage of the test scores are below 90? b) What percentage of
the test scores are above 75? c) What percentage of students have
test scores between 80 and 93? d) What test score is at the 95th
percentile?

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 2 minutes ago

asked 14 minutes ago

asked 21 minutes ago

asked 26 minutes ago

asked 26 minutes ago

asked 26 minutes ago

asked 26 minutes ago

asked 31 minutes ago

asked 39 minutes ago

asked 40 minutes ago

asked 43 minutes ago

asked 44 minutes ago