SOLUTION: A student doing an internship at a large research firm collected the following data, representing all of the studies the firm had conducted over the past 3 years. What is the p

Question 1143688: A student doing an internship at a large research firm collected the following data, representing all of the studies the firm had conducted over the past 3 years.

What is the probability that the study did not use randomization, if we already know that the study was a retrospective observational study?

Randomization? Retrospective Observational Prospective Observational Experiment Total
Yes 7 28 35 70
No 53 62 115 230
Total 60 90 150 300

0.88

0.85

0.27
Answer by ikleyn(52908) (Show Source): You can put this solution on YOUR website!
.
A student doing an internship at a large research firm collected the following data, representing all of the studies
the firm had conducted over the past 3 years.

What is the probability that the study did not use randomization, if we already know that the study was
a retrospective observational study?

 
Randomization?	Retrospective Observational	Prospective Observational	Experiment	Total
Yes	         7	                        28	                         35	          70
No	        53	                        62	                        115	         230
Total	        60	                        90	                        150	         300

	
Answer options
0.88
	
0.85
	
0.27

~~~~~~~~~~~~~~~~~~~~~~~

What you see above -- is your post.

Please pay attention on how I EDITED (formatted) it TO MAKE SENSE.

ANSWER.    P =  = 0.88  (correct with 2 decimal places)


Although the formula is SELF-EXPLANATORY, I will give some explanation.


    Go to the column "Retrospective Observational", take there two appropriate numbers "53" and "60" and make a ratio.

RELATED QUESTIONS
A student's pay of $22 an hour is $5 more than twice the amount the student earns per... (answered by solver91311)

A large biotech firm uses two computers to process the daily results of its research... (answered by ikleyn)

in a class of 24 students 19 take social studies, 22 take math and all take either social (answered by scott8148)

In an effort to estimate the mean amount spent per customer for dinner at an Koket... (answered by ikleyn)

Translating research questions into hypotheses. Translate each of the following research... (answered by Boreal)

I have two questions that I am in dire need of answers to. I have been stumped for 3... (answered by scott8148)

QUESTIONS 4 It is recently found that eating eggs does not increase a person’s... (answered by ikleyn)

KSDLD-Pros, an IT Project consulting firm, is forming an IT Project management team of 5... (answered by mathmate)

Answer the following problems. 1. What is the probability of drawing an ace or a king... (answered by ikleyn)