Question

Mrs. Smith has taught three, Algebra I classes this year. She just finished grading her final chapter test for the second semester. The raw data is below:
Class A Class B Class C
80 72 100
85 90 90
87 85 94
92 84 100
86 91 75
90 78 30
94 94 94
100 86 72
75 82 85
45 78 87
85 86 42
38 78 100
72 95 90
94 90 94
62 88 60

Analyze the data for Class A and Class B.

Answer 1

Part 1: What is the mean and standard deviation for Classes A and B?
Part 2: Make a box plot of the data for Classes A and B. Identify the median, first and third quartiles, minimum and maximum data points.
Part 3: Explain how the values for Classes A and B vary about the mean and median. What information does this give Mrs. Smith?

Answer 2

@ganeshie8 can you help me ?

Answer 3

for part a,
do u know how to find "mean" ?

Answer 4

i believe so but i dont know wat standard diviation is.

Answer 5

one sec

Answer 6

so, looks like u have 15 students here

Answer 7

and we dont need to worry about Class C i think....

Answer 8

yea they just said to look at a and B

Answer 9

lets delete Class C first

Answer 10

```
Class A Class B
80 72
85 90
87 85
92 84
86 91
90 78
94 94
100 86
75 82
45 78
85 86
38 78
72 95
94 90
62 88
--------------------

```

Answer 11

Add the stuff in each column and divide by 15,
u wud get mean.

Answer 12

so for class A i got 79 and im still working on class B

Answer 13

okay, once u finish mean, we can work on std dev...

Answer 14

i didnt get a whole number i got 85.62

Answer 15

mean = 79 is correct for Class A :

http://www.wolframalpha.com/input/?i=mean+%7B80+85+87+92+86+90+94+100+75+45+85+38+72+94+62%7D

Answer 16

for Class B, you should get mean = 85.133 :

http://www.wolframalpha.com/input/?i=mean+%7B72+90+85+84+91+78+94+86+82+78+86+78+95+90+88%7D

Answer 17

check ur calculation again

Answer 18

For standard deviation, we can use below formula :
http://www.revisionworld.com/sites/revisionworld.com/files/imce/sdeviation2.gif

Answer 19

yea never mind your right i forgot to add 2 of the numbers

Answer 20

standard deviation for Class A :

http://www.wolframalpha.com/input/?i=standard+deviation+%7B80+85+87+92+86+90+94+100+75+45+85+38+72+94+62%7D&a=*C.standard+deviation-_*PopulationStandardDeviation-


standard deviation for Class B :

http://www.wolframalpha.com/input/?i=standard+deviation+%7B72+90+85+84+91+78+94+86+82+78+86+78+95+90+88%7D&a=*C.standard+deviation-_*PopulationStandardDeviation-

Answer 21

you wud get those numbers if u apply that formula and calculate manually... but nobody does it manually... doing it for 15 students is very painful... so... just use wolfram maybe..

Answer 22

for Part 2,
first, u need to find our "median", "first quartile" and "third quartile"

Answer 23

knw how to find them ?

Answer 24

i know how to find the median

Answer 25

class B's median is 86

Answer 26

wait can we take a step back really quick so the standard devaition for part A is 17.432 and for part B it is 6.3442

Answer 27

thats right !

Answer 28

For Class A, after calculating everything and plotting box-plot, you should have something like below :
http://prntscr.com/3bkfyu

Answer 29

For Class B :

http://prntscr.com/3bkhys

Answer 30

let me knw if u have any questions.. calculating median/first quartile/third quartiles are pretty easy... u just need to sort the data :

Since there are 15 observations,
4th observation = first quartile
8th observation = median
12th observation = third quartile

Answer 31

ok thx

Answer 32

hope u can answer the part 3, by looking at both box plots side by side... good luck !

Answer 33

k thank you sooooo much for your help.

Answer 34

np :)

Answer 35

@experimentX can you help me with a couple questions with the graph at the top of this post?

Answer 36

Question 2
Analyze and compare the data for Class B and Class C.
• Part 1: Make a dot plot for each of Classes B and C.
• Part 2: What information is easily seen from the dot plots for Classes B and C?
• Part 3: Look at the box plot and dot plot created for Class B. What are the strengths and weaknesses of each type of plot?
• Part 4: Which of the two classes (B or C) performed better on the test? Justify your conclusion.

Answer 37

?? I am not good with stat and probability ... btw @ganeshie8 how do you put that thing into <code></code> tag?

Answer 38

ok thx anyway. @experimentX

Answer 39

@mathslover @thomaster can any of you help me with the last four questions?

Answer 40

@experimentX copy paste below :

```
\```
afjkadsfkakjkalf
\```
```

Answer 41

```
afjkadsfkakjkalf
asd
sdfasfasfd
asdfsfasdf
asdfasdf
ffsdfa
```
interesting!!

Answer 42

Part 3: Explain how the values for Classes A and B vary about the mean and median. What information does this give Mrs. Smith?
can someone help me
dominiquebee72

Answer 43

@ganeshie8