Data Analysis - SPSS

1. HOMEWORK 1 Data Analysis for Hospitality Managers
(Due: Apr. 15th
)
Rahel Hailu
1. Last year an accounting firm paid each of its six clerks $25,000, its two junior
accountants $60,000 each, and the firm’s owner $255,000.
a. What is the mean salary paid at this firm? How many of the employees earn less
than the mean? What is the mode and median of salary?
Mean= (25,000*6+60,000*2+225,000)/9 = $55,000
Mode=$25,000
Median=$25,000
b. Find the range and IQR. Which one is a better measure of dispersion? Why?
Range= 225,000-25,000=200,000
Q1= 0.25*9 = 2.25cases------ 25,000
Q3= 0.75*9= 6.75 cases------ 60,000
IQR= 35,000 (60000-25000), this one is better than range, in case of range
there are outliners, it shows range bigger, however IQR is better measurement
than range.
c. This year, the same firm gives no raise to the clerks and junior accountants, while
the owner’s take increases to $455,000. How does this change affect the mean?
How does it affect the median? (You don’t have to recalculate the mean and
median!! Just guess.)
Since the owner salary increases from 255,000 to 455000, definitely it affects
mean, though the median still the same.
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2. (SPSS)
Using the data file “marketing” to answer following questions.
1. There are 8 variables except for ID. Fill the box below.
Variables Level of
Measurement
Appropriate
Central Tendency
Measure
Appropriate
Dispersion
Measure
Visday Nominal Mode None
Vistime Nominal Mode None
Menu Nominal Mode None
recommend Ordinal Median IQR
Satisfied Ordinal Median IQR
Amount Scale Median/ mean SD
Income Ordinal Mode/ Median SD
frequency Scale Mode/Median SD
2. Produce a frequency table and a bar chart for “menu”.
menu category
Frequency Percent Valid Percent
Cumulative
Percent
Valid healthy food 141 31.3 31.3 31.3
seasonal food 210 46.7 46.7 78.0
regular food 99 22.0 22.0 100.0
Total 450 100.0 100.0
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3. 3. Produce a proper kind of graph to show the distribution of “amount.”
4. Based on the graph you made in question 3, describe the shape of the distribution.
Guess which one would be higher, mean or median? Why?
Positive skewness - long tail in the right side.
Long tail in the right side, - Mean is higher than median;
5. Confirm your answer to the question 4 by finding appropriate measures of central
tendency.
Refer to question #1, “Amount” is scale. Therefore, Central tendency are mean
and median
6. Find the range, IQR, and standard deviation of the variable “amount”.
The Range is 74,300
The IQR is 75%-25%-- 14,900 (36,900-22,000).
And the SD is 11120.853
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4. Statistics
amount spent
N Valid 450
Missing 0
Mean 29940.00
Median 29750.00
Range 74300
Percentiles 25 22000.00
50 29750.00
75 36900.00
7. Find the median, range, and IQR of “amount” for each of daytime visitors and
evening visitors, separately.
Statistics vistime = 1
amount spent
N
Valid 180
Missing 0
Median 25100.00
Range 40500
Percentiles
25 20300.00
50 25100.00
75 30825.00
Statistics vistime = 2
amount spent
N
Valid 270
Missing 0
Median 32650.00
Range 73200
Percentiles
25 26200.00
50 32650.00
75 37900.00
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5. 8. Make a box-plot for amount for all visitors, and also for daytime visitors and
evening visitors, separately. Describe what you find in a couple of sentences.
In comparison to the amount for daytime and night time visitors, evening visitors amount
are higher than daytime visitors. Therefore, amount for evening consumers are superior
than daytime.
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6. 9. Get the means and standard deviations for each of daytime visitors and evening
visitors. Which group spent more? Which group is diverse in the amount spent?
Statistics- Daytime
amount spent
N
Valid 180
Missing 0
Mean 25490.00
Std. Deviation 8556.771
Statistics- Evening
amount spent
N
Valid 270
Missing 0
Mean 32906.67
Std. Deviation 11645.716
Mean and the SD - evening visitors paying are higher than daytime visitors.
-Evening visitors spent more than daytime.
- Std. Deviation shows, distribution diverse of the amount. Henceforth, the
evening visitors groups have diversification than the daytimevisitors.
10. Final question. Do you think that the difference between the two groups (daytime
vs. evening) in the mean amount is large enough to conclude that one group spent
more than the other? Why or why not? (This topic will be covered in the
inferential statistics later. For now, just guess and tell your ‘impression.’)
I could not determine the mean of day and evening groups spent than one each
other’s, because there are still insignificant error in the sample.
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7. 9. Get the means and standard deviations for each of daytime visitors and evening
visitors. Which group spent more? Which group is diverse in the amount spent?
Statistics- Daytime
amount spent
N
Valid 180
Missing 0
Mean 25490.00
Std. Deviation 8556.771
Statistics- Evening
amount spent
N
Valid 270
Missing 0
Mean 32906.67
Std. Deviation 11645.716
Mean and the SD - evening visitors paying are higher than daytime visitors.
-Evening visitors spent more than daytime.
- Std. Deviation shows, distribution diverse of the amount. Henceforth, the
evening visitors groups have diversification than the daytimevisitors.
10. Final question. Do you think that the difference between the two groups (daytime
vs. evening) in the mean amount is large enough to conclude that one group spent
more than the other? Why or why not? (This topic will be covered in the
inferential statistics later. For now, just guess and tell your ‘impression.’)
I could not determine the mean of day and evening groups spent than one each
other’s, because there are still insignificant error in the sample.
6