calculations in descriptive statistics, homework help

Nov 6th, 2016
SoccerBoss
Category:
Other
Price: $70 USD

Question description

article 

USE THE HARVARD REFERENCING SYSTEM THROUGHOUT THE REPORT

Problem 1 (25 pts)

The cost of 14 models of digitals cameras at a camera specialty store during 2014 was as follows:

340 450 450 280 220 340 290 370 400 310 340 430 270 380

1. Compute mean, median, mode, first and third quartile.

2. Compute the variance, standard deviation, range, interquartile range, coefficient of variation, standard error of the mean and Z scores.

3. Determine whether or not there are outliers? Explain.

4. Determine whether or not the data are skewed? If so, how?

5. Based on the previous results what conclusions can you reach concerning the price of digital cameras at a camera specialty store during 2014.

6. Construct a 90%, 95%, 99% confidence interval for the population mean cost of digitals cameras.

7. Interpret the meaning of each interval.

8. What assumption do you need to make about the population of interest to construct the confidence intervals?

Problem 2 (15 pts)

Consider the sample data for plants A, B, C & D of the above company, which are

tabulated in table 1. Test whether the four means are equal at the 5% level of significance. Perform a test that will compare all 4 means at once. We are not interested in pair-wise comparisons at this stage. Please show all the steps in your calculations.

Table 1:

A B C D

333 328 320 333

332 329 321 321

320 323 322 329

326 327 325 330

328 330 326 328

325 331 328 325

323 332 329 333

321 320 330 331

334 324 331 327

322 323 332

320 334

329

330

328

331

330

Problem 3 (30 pts)

Read the article attached above (p. 221 – 225)

«Performance and duration differences between online and paper–pencil tests» and answer the questions below.

Part A.

1. Develop a 95% confidence interval using data from this study.

2. Perform a hypothesis testing using data from this study.

(show all the the appropriate steps).

3. Suggest another statistical technique(s) for the purpose of this study. Explain.

Part B.

For this study briefly describe how the researcher draw conclusions from a sample about a population. Try to be as analytic as possible and use the comments bellow.

1. Determine (or define) the independent variable(s).

2. Determine (or define) the dependent variable(s).

3. Determine (or define) qualitative and quantitative variable(s).

4. Determine (or define) the sample and the population.

5. Describe the statistical method(s) being used and define inferential statistics. Interpret the meaning of p-value.


Tutor Answer

(Top Tutor) Daniel C.
(997)
School: UCLA
PREMIUM TUTOR

Hi hamidsabah, Please check the attached file for detail, let me know if you have any questions, thank you. Best, James,

1.
Mean= (340+450+450+280+220+340+290+370+400+310+340+430+270+380)/14
=347.86
Reorder the list from minimum to maximum:
220, 270,280,290,310,340,340,340,370,380,400,430,450,450
Since the number of element in the list in even, the median is the average of 7th and 8th element
Median = (340+340)/2 = 340
340 appears 3 times in the list and is the most frequent, thus
Mode = 340
The 1st quantile is the median of the first half of the ordered list
220, 270,280,290,310,340,340
1st quantile = 290
3rd quantile is the median of second half of the ordered list
340,370,380,400,430,450,450
3rdquantile = 400
2.
Variance = {(340-347.86)2+(450-347.86)2+(280-347.86)2+(220-347.86)2+(340-347.86)2+(290-347.86)2
+(370-347.86)2+(400-347.86)2+(310-347.86)2+(340-347.86)2+(430-347.86)2+(450-347.86)2+
(450-347.86)2}/(14-1)
=4910.440
Standard deviation = (variance)1/2 = 70.075
The range of a set of data is the difference between the highest and lowest elements in the set.
Range = 450-220 = 230
interquartile range is difference betw...

Studypool has helped 1,244,100 students

8 Reviews


Summary
Quality
Communication
On Time
Value
tinytim47
Nov 29th, 2016
" Wow this is really good.... didn't expect it. Sweet!!!! "
Five Star Tutor
Nov 20th, 2016
" Outstanding Job!!!! "
mixedballz
Nov 16th, 2016
" excellent work as always thanks for the help "
lilmoe415
Nov 7th, 2016
" Thank you, Thank you, for top quality work, this is your guy!! "
darnay
Oct 24th, 2016
" The best tutor out there!!!! "
dontuwannaknow
Oct 15th, 2016
" Excellent work as always thanks so much "
SjSurvivor143
Oct 2nd, 2016
" Thanks for the help. "
Joemoe
Sep 18th, 2016
" <3 it, thanks for saving me time. "
Ask your homework questions. Receive quality answers!

Type your question here (or upload an image)

1829 tutors are online

Brown University





1271 Tutors

California Institute of Technology




2131 Tutors

Carnegie Mellon University




982 Tutors

Columbia University





1256 Tutors

Dartmouth University





2113 Tutors

Emory University





2279 Tutors

Harvard University





599 Tutors

Massachusetts Institute of Technology



2319 Tutors

New York University





1645 Tutors

Notre Dam University





1911 Tutors

Oklahoma University





2122 Tutors

Pennsylvania State University





932 Tutors

Princeton University





1211 Tutors

Stanford University





983 Tutors

University of California





1282 Tutors

Oxford University





123 Tutors

Yale University





2325 Tutors