Question

A professor wants to know if her introductory statistics class has a good grasp of basic

math. Six students are chosen at random from the class and given a math proficiency

test. The six students score a sample average of 60.83 with a sample standard deviation of 13.17. Can the professor conclude that the mean score for the class on the test would

be below 70? Use a significance level of 0.05

Answer #1

Hypothesis: Vs

Since the population standard deviation is not known.

Therefore , use t-distribution.

Now , df=degrees of freedom-n-1=6-1=5

Therefore , the critical value is ,

The test statistic is ,

Decision : Here , the value of the test statistic does not lies in the rejection region.

Therefore , fail to reject Ho.

Conclusion : Hence , there is not sufficient evidence to conclude that the the mean score for the class on the test would be below 70.

Question 1
The main reason a research uses a t-test instead of a z-test is
when little is known about population (mean and standard
deviation).
1) True
2) False
Question 2
Values in the t‐table are not actually listed by sample
size but by degrees of freedom (df).
1) True
2) False
Question 3
A 90 percent confidence level is equivalent to an alpha level of
0.10
1) True
2) False
Question 4
A professor wants to know if her...

The average test score for the statistics course is 74%. A
professor wants to see if the average test score for students who
are given colored pens on the first day of class is higher. The
test scores for the 12 randomly selected students who were given
the colored pens are shown below. Assume that the distribution of
the population is normal.
81, 61, 86, 63, 74, 91, 62, 70, 80, 94, 70, 87
What can be concluded at the...

5. In a large class of introductory Statistics students, the
professor has each person toss a fair coin 11 times and calculate
the proportion of his or her tosses that were heads. The students
then report their results, and the professor plots a histogram of
these several proportions.
a) What shape would you expect this histogram to be? Why?
b) Where do you expect the histogram to be centered?
c) How much variability would you expect among these
proportions?
d)...

In a large class of introductory Statistics students, the
professor has each person toss a fair coin 12 times and calculate
the proportion of his or her tosses that were heads. The students
then report their results, and the professor plots a histogram of
these several proportions. a) What shape would you expect this
histogram to be? Why? b) Where do you expect the histogram to be
centered? c) How much variability would you expect among these
proportions? d) Explain...

Students believe that Professor A has a lower class mean exam
score than Professor B. To test this claim, 40 randomly chosen
exams were selected from professor A and 26 exams were randomly
selected from Professor B. Professor A had a sample mean of 80 with
a sample standard deviation of 10. Professor B had a sample mean of
86 with a standard deviation of 14. Assume the exam scores are
normally distributed for both professors.
Use the PHANTOMS steps...

A teacher wants to know how well the students in her gifted
class perform relative to her other classes. She administers a
standardized test to all of her classes, which has a mean of 50
(SD = 10). Her gifted class of 31 students has an average
score of 55. She want to know what percent of all of her classes
score lower than her gifted class.
Null hypothesis
Alternative hypothesis
IVs
DVs
Best test to use
Results Write-Up

A high school math teacher claims that students in her class
will score higher on the math portion of the ACT then students in a
colleague’s math class. The mean ACT math score for 49 students in
her class is 22.1 and the standard deviation is 4.8. The mean ACT
math score for 44 of the colleague’s students is 19.8 and the
standard deviation is 5.4. At α = 0.05, can the teacher’s claim be
supported?
a. Write down the...

1. A statistics professor is examining if using the book in his
class has any impact on student test scores. For a sample of 30
Statistics students who were required to buy and read the book for
class, final semester grades were measured at the end of the
semester. The mean final grade for this class was 87. If the mean
final grade for all the previous classes (where students had not
been required to use the book) was 83...

In a large class of introductory Statistics students, the
professor has each person toss a coin 2121 times and calculate the
proportion of his or her tosses that were heads.
a) Confirm that you can use a Normal model here.
The Independence Assumption▼a)is not b)is satisfied because the
sample proportions ▼a) are not b)are independent of each other
since one sample proportion ▼ a)does not affect b)can affect
another sample proportion. The Success/Failure Condition ▼ a) is
not b) is...

A college professor claims that the entering class this year
appears to be smarter than entering classes from previous years. He
tests a random sample of 15 of this year's entering students and
finds that their mean IQ score is 113, with standard deviation of
15. The college records indicate that the mean IQ score for
entering students from previous years is 112. If we assume that the
IQ scores of this year's entering class are normally distributed,
is there...

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 2 minutes ago

asked 8 minutes ago

asked 27 minutes ago

asked 30 minutes ago

asked 44 minutes ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 2 hours ago

asked 2 hours ago