8.14 test for a significant difference in the variances of the

8.14 Test for a significant difference in the variances of the initial white blood cell count between patients who did and patients who did not receive a bacterial culture.

 

8.15 What is the appropriate test procedure to test for significant differences in mean white blood cell count between people who do and people who do not receive a bacterial culture?

8.18 Compute a 95% CI for the true difference in mean white blood cell count between the two groups.

 

A 1980 study was conducted whose purpose was to compare the indoor air quality in offices where smoking was permitted with that in offices where smoking was not permitted [7]. Measurements were made of carbon monoxide (CO) at 1:20 p.m. in 40 work areas where smoking was permitted and in 40 work areas where smoking was not permitted. Where smoking was permitted, the mean CO level was 11.6 parts per million (ppm) and the standard deviation CO was 7.3 ppm. Where smoking was not permitted, the mean CO was 6.9 ppm and the standard deviation CO was 2.7 ppm.

 

a)      State the null hypothesis

Null hypothesis: There is no significant difference between the mean CO level in institutions where smoking is permitted and institutions where smoking is not permitted.

 

b)     State the alternative hypotheses

There is a significant difference between the mean CO level in institutions where smoking is permitted and institutions where smoking is not permitted.

 

c)      show the test statistics.

Work areas (1)=40

Work areas 2=40

Standard deviation of work area 1= 11.6

Standard deviation of work area 2= 2.7

Mean of work area 2= 6.9

Mean of work area 1= 7.3

 

Ho= standard dev1=standard dev2

Ha= standard dev1 does not equal standard dev 2

 

F test: standard deviation of work area 1^2 / standard deviation of work area 2

7.3^2/2.7^2

7.31

 

DOF= 40-1=39 ( for both)

Critical value = .05

 

8.25 Test for whether the standard deviation of CO is significantly different in the two types of working environments.

 

A camera has been developed to detect the presence of cataract more accurately. Using this camera, the gray level of each point (or pixel) in the lens of a human eye can be characterized into 256 gradations, where a gray level of 1 represents black and a gray level of 256 represents white. To test the camera, photographs were taken of 6 randomly selected normal eyes and 6 randomly selected cataractous eyes (the two groups consist of different people). The median gray level of each eye was computed over the 10,000+ pixels in the lens. The data are given in Table 8.14.

 

 8.28 What statistical procedure can be used to test whether there is a significant difference in the median gray levels between cataractous and normal eyes?

* paired t test?

 

8.29 Carry out the test procedure mentioned in Problem 8.28, and report a p-value.

 

8.30 Provide a 99% CI for the mean difference in median gray levels between cataractous and normal eyes.

 

 

8.39 What is the appropriate test procedure to determine whether there is a systematic difference between the assessments of Doctor A vs. Doctor B?

? chi squared analysis?

 

* appropriate statistical procedure

* why?

 

 

 

 

8.56 What test can be performed to compare the variances of the two genotype groups?

 

 

 

8.92 What test can be used to compare the mean ln (ERG amplitude) between patients with dominant vs. recessive RP?

 

 

Order a unique copy of this paper
(550 words)

Approximate price: $22

Basic features
  • Free title page and bibliography
  • Unlimited revisions
  • Plagiarism-free guarantee
  • Money-back guarantee
  • 24/7 support
On-demand options
  • Writer’s samples
  • Part-by-part delivery
  • Overnight delivery
  • Copies of used sources
  • Expert Proofreading
Paper format
  • 275 words per page
  • 12 pt Arial/Times New Roman
  • Double line spacing
  • Any citation style (APA, MLA, Chicago/Turabian, Harvard)

Our guarantees

We value our customers and so we ensure that what we do is 100% original..
With us you are guaranteed of quality work done by our qualified experts.Your information and everything that you do with us is kept completely confidential.

Money-back guarantee

You have to be 100% sure of the quality of your product to give a money-back guarantee. This describes us perfectly. Make sure that this guarantee is totally transparent.

Read more

Zero-plagiarism guarantee

The Product ordered is guaranteed to be original. Orders are checked by the most advanced anti-plagiarism software in the market to assure that the Product is 100% original. The Company has a zero tolerance policy for plagiarism.

Read more

Free-revision policy

The Free Revision policy is a courtesy service that the Company provides to help ensure Customer’s total satisfaction with the completed Order. To receive free revision the Company requires that the Customer provide the request within fourteen (14) days from the first completion date and within a period of thirty (30) days for dissertations.

Read more

Privacy policy

The Company is committed to protect the privacy of the Customer and it will never resell or share any of Customer’s personal information, including credit card data, with any third party. All the online transactions are processed through the secure and reliable online payment systems.

Read more

Fair-cooperation guarantee

By placing an order with us, you agree to the service we provide. We will endear to do all that it takes to deliver a comprehensive paper as per your requirements. We also count on your cooperation to ensure that we deliver on this mandate.

Read more

Calculate the price of your order

550 words
We'll send you the first draft for approval by September 11, 2018 at 10:52 AM
Total price:
$26
The price is based on these factors:
Academic level
Number of pages
Urgency