Question
In: Statistics and Probability
A certain survey is conducted by choosing randomly 10 students and asked them about the number...
A certain survey is conducted by choosing randomly 10 students and asked them about the number of hours each of them spent on preparing for a final exam. The following are their answers to the question: 6,11,8,7,4,14,1,10,5,12
a- Construct the boxplot for the time spent studying for the exam.
b- Describe the distribution of the time spent studying for the exam
c- Find a 99% confidence interval for the mean time spent for studying
d- Interpret the confidence interval in (c).
Solutions
Expert Solution
Given:
A certain survey is conducted by choosing randomly 10 students and asked them about the number of hours each of them spent on preparing for a final exam.
The following are their answers to the question: 6,11,8,7,4,14,1,10,5,12 :
Arrange the given data in ascending order
1, 4, 5, 6, 7, 8, 10, 11, 12, 14
Five numbers summary :
Minimum = 1
First quartile, Q1 : first quartile is the median of the first half of the data
Q1 = 5
Median, Q2 = (7+8)/2 = 7.5
Third quartile, Q3 : Third quartile is the median of the second half of the data.
Q3 = 11
Maximum = 14
The boxplot for the time spent studying :
b) Since mean = 7.8 > median = 7.5, the distribution is positively skewed or skewed to right.
d) Interpretation :
We are 99% confident that the mean time spent for studying is between 3.70 and 11.90
orchestra answered 1 year agoRelated Solutions
Fifty randomly selected students were asked the number of movies they watched them previous week. The...
Fifty randomly selected students were asked the number of
movies they watched them previous week. The results are as
follows:
# of Movies
# of Movies | Student Frequency
0. 10
1 . 18
2 . 12
3 . 8
4 . 2
a) Find the sample mean, median, and range of the sample. .
b) Find the standard deviation and the variance.
c) Find the first quartile. (1 mark)
d) Find the second quartile. To which value it corresponds?...
A research group conducted a survey about church attendance. The survey respondents were asked about their...
A research group conducted a survey about church attendance. The
survey respondents were asked about their church attendance and
asked to indicate their age. The results are as follows:
Church Attendance
Age
20 to 29
30 to 39
40 to 49
50 to 59
Yes
60
30
68
100
No
87
107
80
50
Answer the following four questions. Use 5% level of
significance throughout.
1.We use the sample data above to determine whether church
attendance is independent of age....
A survey of 200 students is selected randomly on a large university campus They are asked...
A survey of 200 students is selected randomly on a large
university campus They are asked if they use a laptop in class to
take notes. The result of the survey is that 70 of the 200 students
use laptops to take notes in class.
What is the value of the sample proportion? (0.5
pts)
What is the standard error of the sampling proportion?
(0.5 pts)
Construct an approximate 95% confidence interval for the true
proportion by going 2 standard...
A survey of 150 students is selected randomly on a large university campus. They are asked...
A survey of 150 students is selected randomly on a large
university campus. They are asked if they use a laptop in class to
take notes. The result of the survey is that 60 of the 150 students
responded "yes." An approximate 98% confidence interval is
(0.307, 0.493). Complete parts a through d below. b) How would
the confidence interval change if the sample size had been 375
instead of 150? (Assume the same sample proportion.) The new
confidence interval...
A survey of 200 students is selected randomly on a large university campus. They are asked...
A survey of 200 students is selected randomly on a large
university campus. They are asked if they use a laptop in class to
take notes. Suppose that based on the survey, 80 of the 200
students responded "yes."
a) What is the value of the sample proportion ModifyingAbove p
with caret?
b) What is the standard error of the sample proportion?
c) Construct an approximate 95% confidence interval for the
true proportion p by taking plus or minus 2...
A survey of 250 students is selected randomly on a large university campus. They are asked...
A survey of 250 students is selected randomly on a large
university campus. They are asked if they use a laptop in class to
take notes. The result of the survey is that 115 of the 250
students responded "yes." An approximate 95% confidence interval
is (0.397,0.523). Which of the following are true? If they are
not true, briefly explain why not
a)95% of the students fall in the interval
(0.397,0.523).
b) The true proportion of students who use laptops...
A survey of the mean number of cents off that coupons give was conducted by randomly...
A survey of the mean number of cents off that coupons give was
conducted by randomly surveying one coupon per page from the coupon
sections of a recent Rockford newspaper. The following data were
collected: 20¢; 75¢; 50¢; 75¢; 30¢; 55¢; 10¢; 40¢; 30¢; 55¢; $1.50;
40¢; 65¢; 40¢. Assume the underlying distribution is approximately
normal. Construct a 95% confidence interval for the population mean
worth of coupons. Find the lower limit of the confidence interval.
Enter it rounded to...
A survey of the mean number of cents off that coupons give was conducted by randomly...
A survey of the mean number of cents off that coupons give was
conducted by randomly surveying one coupon per page from the coupon
sections of a recent San Jose Mercury News. The following data were
collected: 20¢; 75¢; 50¢; 65¢; 30¢; 55¢; 40¢; 40¢; 30¢; 55¢; $1.50;
40¢; 65¢; 40¢. Assume the underlying distribution is approximately
normal.
Construct a 95% confidence interval for the population mean
worth of coupons. Use a critical value of 2.16 from the
t distribution.
A survey of the mean number of cents off that coupons give was conducted by randomly...
A survey of the mean number of cents off that coupons give was
conducted by randomly surveying one coupon per page from the coupon
sections of a recent San Jose Mercury News. The following data were
collected: 20¢; 75¢; 50¢; 65¢; 30¢; 55¢; 40¢; 40¢; 30¢; 55¢; $1.50;
40¢; 65¢; 40¢. Assume the underlying distribution is
approximately normal. You wish to conduct a hypothesis test (α
= 0.05 level) to determine if the mean cents off for coupons is
less...
A survey of the mean number of cents off that coupons give was conducted by randomly...
A survey of the mean number of cents off that coupons give was
conducted by randomly surveying one coupon per page from the coupon
sections of a recent San Jose Mercury News. The following data were
collected: 20¢; 75¢; 50¢; 65¢; 30¢; 55¢; 40¢; 40¢; 30¢; 55¢; $1.50;
40¢; 65¢; 40¢. Assume the underlying distribution is
approximately normal. You wish to conduct a hypothesis test (α
= 0.05 level) to determine if the mean cents off for coupons is
less...
ADVERTISEMENT
ADVERTISEMENT
Latest Questions
- I crushed acetamide and heated until melted, i let it cool and started again. Melting Point...
- A certain company;s cash flows are expected to grow at a rate of 20% for the...
- The reservation office for Central Airlines has two agents answering incoming phone calls for flight reservations....
- Financial Statements Jose Loder established Bronco Consulting on August 1, 2019. The effect of each transaction...
- How should the “self-reference criterion” be applied by a leader leading a culturally diverse group in...
- C/C++ Programming in a UNIX Environment, You should have read permission for the/etc/passwdfile. To answer the...
- A company is considering the purchase of a new piece of equipment for $91,600. Predicted annual...
ADVERTISEMENT