Question

Data Set for Project 1
Maximum Temperatures by State
in the United States
for the month of August, 2013
State Name	Max Temps in August 2013
AL	97
AK	97
AZ	45
AR	100
CA	49
CO	109
CT	93
DE	91
FL	102
GA	99
HI	90
ID	97
IL	97
IN	93
IA	100
KS	111
KY	93
LA	97
ME	93
MD	97
MA	97
MI	91
MN	109
MS	97
MO	97
MT	90
NE	108
NV	111
NH	93
NJ	108
NM	106
NY	93
NC	100
ND	88
OH	91
OK	108
OR	97
PA	93
RI	104
SC	97
SD	93
TN	99
TX	104
UT	106
VT	91
VA	102
WA	93
WV	91
WI	90
WY	99

1. Open a blank Excel file and create a grouped frequency distribution of the maximum daily temperatures for the 50 states for a 30 day period. Use 8 classes.
2. Add midpoint, relative frequency, and cumulative frequency columns to your frequency distribution.
3. Create a frequency histogram using Excel. You will probably need to load the Data Analysis add-in within Excel. If you do not know how to create a histogram in Excel, view the video located at: http://www.youtube.com/watch?v=_gQUcRwDiik. A simple bar graph will also work.

If you cannot get the histogram or bar graph features to work, you may draw a histogram by hand and then scan or take a photo (your phone can probably do this) of your drawing and email it to your instructor.

4. Create an ogive in Excel (or by hand).
5. A. Do any of the temperatures appear to be unrealistic or in error? If yes, which ones and why?

B. Explain how this affects your confidence in the validity of this data set.

Project 1 is due by 11:59 p.m. (ET) on Monday of Module/Week 1.

please help!!!!!!!!

Answer 1

The frequency distribution and the Ogive curve for the data values are obtained in excel by following these steps,

Step 1: Write the data values in excel. The screenshot is shown below,

Step 2: The minimum and maximum value are obtained in excel. The screenshot is shown below,

Hence the classes for the data values are,

Classes
44-52.5
52.5-61
61-69.5
69.5-78
78-86.5
86.5-95
95-103.5
103.5-112

Step 3: Make a column bin with the upper-class limit of the classes then

DATA > Data Analysis > Histogram > OK. The screenshot is shown below,

Step 4: Insert Input Range: Data column, Bin Range: bin column then OK. The screenshot is shown below,

The frequency histogram is obtained. The screenshot is shown below,

Classes	Frequency
44-52.5	2
52.5-61	0
61-69.5	0
69.5-78	0
78-86.5	0
86.5-95	18
95-103.5	19
103.5-112	11

Step 5: Calculate the cummulative frequencies by adding the frequency.

Bin	Frequency	Cummulative freq
52.5	2	2
61	0	2
69.5	0	2
78	0	2
86.5	0	2
95	18	20
103.5	19	39
112	11	50

Step 6: Select the Bin and cumulative frequency column then goto INSERT > Recommended Charts > Scatter with Straight Lines and Markers. The screenshot is shown below,

A) There are two data points (45 and 49) which appear to be unrealistic as these data points lie far below from the rest of the data points.

B) Since these two outlier data points cause the skewness in the distribution, the validity of this data set affected.