Davina D.

asked • 03/22/16

can somone please check my work.

The data from placebo 0mg is listed below.
57,27,32,31,34,38,71,33,34,53,36,42,26,52,36,55,36,42,36,54,34,29,33,33
 
 
What is the mean number of correct responses of the participants after taking the placebo (0 mg/kg)?
 
after adding all of the numbers i get 954 in which i then divide by the total of numbers which is 24 leaving me with
 
954/24 = 39.75 for the mean.
 
What are the standard deviation and the interquartile range of the d0 condition?
 
With this one its a little more complicated.
 
DATA   /  MEAN   /   ANSWER   /   SQUARED
 
57 - 39.75 = 17.25 = 297.5625
27 - 39.75 = -12.75 = -162.5625
32 - 39.75 = -7.75 = -60.0625
31 - 39.75 = -8.75 = -76.5625
34 - 39.75 = -5.75 = -33.0625
38 - 39.75 = -1.75 = -3.0625
71 - 39.75 = 31.25 = 976.5625
33 - 39.75 = -6.75 = -45.5625
34 - 39.75 = -5.75 = -33.0625
53 - 39.75 = 23.25 = 540.5625
36 - 39.75 = -3.75 = -14.0625
42 - 39.75 = 2.25 = 5.0625
26 - 39.75 = -13.75 = -189.0625
52 - 39.75 = 12.25 = 150.0625
36 - 39.75 = -3.75 = -14.0625
55 - 39.75 = 21.25 = 451.5625
36 - 39.75 = -3.75 = -14.0625
42 - 39.75 = 2.25 = 5.0625
36 - 39.75 = -3.75 = -14.0625
54 - 39.75 = 14.25 = 203.0625
34 - 39.75 = -5.75 = -33.0625
29 - 39.75 = -10.75 = -115.5625
33 - 39.75 = -6.75 = -45.5625
33 - 39.75 = -6.75 = -45.5625
 
squared total = 1730.5 (variance)
 
standard deviation
σ=√1730.5
=41.599279
=42
 
 
 

2 Answers By Expert Tutors

By:

Arnold F. answered • 03/22/16

Tutor
5 (53)

College Professor & Expert Tutor In Statistics and Calculus

Davina D.

if squares cant be negative then i am not sure what i am doing wrong being that is the answer I come up with. So what do i do for the equations that are negative
Report

03/23/16

Arnold F.

Negative times a negative is a positive.
 
Change your negatives to positives; re add to get sum of squares; divide by n; take the square root; that should be the standard deviation.
Report

03/23/16

Davina D.

oh okay i see what i did wrong. okay that makes sense.
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03/23/16

Arnold F.

Glad I could help.
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03/23/16

Dan S. answered • 03/22/16

Tutor
4.9 (226)

Mr. Dan Math Tutor

Davina D.

so is my answer correct or incorrect because i have two different answers and i am not sure if i am doing this right. some of my answers are negative and i cant change that and the next step is to square them but if it cant be negative then what am i doing wrong?
Report

03/23/16

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