In: Statistics and Probability
The goal of this lab is to standardize data, to compute probabilities using the standard normal distribution, and to find values given probabilities. Use the Lab Data Set provided to answer all questions. (all of the data is at the bottom of the post.
1. Use Microsoft Excel to compute the mean and standard deviation of Net Sales for the Patagonia file.
Mean:
Standard deviation:
2. Sort the list of 100 data values from smallest to largest, using
Microsoft Excel. Write down the raw scores (x values) on lines #1,
#20, and #100. Compute the corresponding z-scores by using
the formula for calculating z scores. Round to two decimal places.
Finally, look up the z score on the appropriate table and place the
value of the cumulative area to the left of your z score on the
table below.
Line # |
x value |
z - score |
Value in Z table |
2 |
Low value (L) =$27.07 |
||
51 |
Middle Value (M) =$164.71 |
||
101 |
High Value (H) = $295.56 |
3. Using the mean and standard deviation from #1 above, and using the formula x = m + zs , find the data value x that goes with the following z-scores. Use x = m and s = s .
z – score |
x value |
z = -2.50 |
|
z = 3.20 |
|
z = 0 |
|
z = 0.5 |
For the rest of the lab, you will make the assumption that your data is approximately normally distributed. Use Excel to answer the following questions for the Net Sales data. Copy and paste the output below, don’t include as a separate file, make sure your x axis is labelled properly. You will have to “insert” your graphs in the appropriate places below. Please don’t upload more than one file for me to open and grade, your entire lab should be in ONE uploaded file. If you can’t do that, then print out the separate files and then scan it in as one file, but you should be able to figure out how to copy and paste all your answers into one document.
4. Locate your lowest x value (L) and your highest x value (H) on the axis.
Shade the area between x=L and x=H.
Find the value of the shaded area under the curve. In other words, what is P(L< x<H)?
5. Locate your middle x value (M) and your highest x value (H) on the axis.
Shade the area between x=M and x=H.
Find the value of the shaded area under the curve. In other words, what is P(M< x<H)?
6. Locate your highest x value (H) and your highest x value on the axis.
Shade the area to the right of x=H.
Find the value of the shaded area under the curve. In other words, what is P(x>H)?
7. Shade the area where the lowest 10% of the values would be.
What is the Z-score for this area? _________________
What is the x-value for this area? __________________
8. Shade the area where the top 5% of your values would be.
What is the z-score for this area? _________________
What is the x-value for this area? _________________
Row | Items | Sales | Card Type | Gender | Country | Age | Martial Status |
1 | 19 | $50.61 | visa-electron | Male | China | 35 | 2 |
2 | 14 | $105.37 | mastercard | Female | China | 22 | 2 |
3 | 11 | $90.21 | maestro | Female | Russia | 52 | 2 |
4 | 20 | $280.84 | visa | Male | China | 38 | 1 |
5 | 18 | $265.68 | jcb | Male | China | 44 | 1 |
6 | 19 | $103.63 | americanexpress | Female | Indonesia | 56 | 2 |
7 | 17 | $215.00 | jcb | Male | Dominican Republic | 51 | 1 |
8 | 20 | $168.06 | laser | Male | Czech Republic | 25 | 1 |
9 | 3 | $181.42 | maestro | Female | China | 41 | 1 |
10 | 11 | $240.51 | mastercard | Female | China | 44 | 1 |
11 | 17 | $260.56 | jcb | Male | China | 58 | 1 |
12 | 17 | $170.56 | jcb | Female | Belarus | 28 | 2 |
13 | 14 | $71.42 | diners-club-carte-blanche | Male | Sweden | 41 | 1 |
14 | 3 | $242.23 | diners-club-carte-blanche | Female | Indonesia | 58 | 2 |
15 | 15 | $250.44 | visa-electron | Male | Latvia | 41 | 2 |
16 | 4 | $71.80 | jcb | Male | New Zealand | 20 | 2 |
17 | 6 | $33.62 | diners-club-us-ca | Male | United States | 48 | 2 |
18 | 17 | $81.35 | diners-club-enroute | Female | Colombia | 44 | 2 |
19 | 13 | $67.09 | maestro | Male | China | 53 | 1 |
20 | 3 | $262.41 | jcb | Female | Lithuania | 22 | 1 |
21 | 16 | $204.28 | jcb | Female | Indonesia | 23 | 2 |
22 | 2 | $289.74 | jcb | Female | Vietnam | 28 | 2 |
23 | 1 | $33.45 | china-unionpay | Male | China | 29 | 2 |
24 | 19 | $154.19 | jcb | Female | Botswana | 46 | 2 |
25 | 20 | $43.29 | diners-club-enroute | Male | Argentina | 58 | 2 |
26 | 5 | $96.97 | jcb | Male | Russia | 42 | 2 |
27 | 1 | $46.62 | jcb | Male | Ecuador | 21 | 2 |
28 | 17 | $241.04 | jcb | Male | China | 41 | 1 |
29 | 6 | $251.64 | switch | Female | Sudan | 58 | 1 |
30 | 1 | $115.24 | visa-electron | Female | Canada | 52 | 1 |
31 | 10 | $263.42 | jcb | Male | France | 44 | 2 |
32 | 10 | $274.67 | jcb | Female | Italy | 32 | 2 |
33 | 1 | $69.59 | jcb | Female | Switzerland | 48 | 2 |
34 | 17 | $136.30 | china-unionpay | Male | China | 44 | 2 |
35 | 7 | $201.52 | jcb | Male | Macedonia | 26 | 2 |
36 | 8 | $51.44 | switch | Female | Papua New Guinea | 51 | 1 |
37 | 11 | $52.95 | jcb | Male | Czech Republic | 48 | 2 |
38 | 19 | $162.89 | china-unionpay | Female | China | 36 | 2 |
39 | 5 | $160.09 | jcb | Female | China | 38 | 1 |
40 | 6 | $91.28 | jcb | Female | Brazil | 39 | 1 |
41 | 4 | $140.53 | mastercard | Female | Indonesia | 26 | 2 |
42 | 15 | $190.36 | visa | Male | Greece | 57 | 1 |
43 | 10 | $181.57 | americanexpress | Male | Philippines | 46 | 2 |
44 | 1 | $65.59 | jcb | Female | China | 31 | 1 |
45 | 3 | $49.01 | laser | Female | United States | 49 | 2 |
46 | 16 | $88.05 | jcb | Female | France | 54 | 2 |
47 | 9 | $193.79 | jcb | Male | Indonesia | 38 | 1 |
48 | 5 | $39.55 | mastercard | Female | Indonesia | 24 | 2 |
49 | 1 | $32.56 | jcb | Male | Japan | 23 | 1 |
50 | 2 | $54.52 | china-unionpay | Male | Ireland | 43 | 1 |
51 | 19 | $161.89 | jcb | Male | China | 57 | 1 |
52 | 2 | $59.63 | maestro | Male | Cyprus | 35 | 1 |
53 | 13 | $257.81 | bankcard | Male | China | 38 | 1 |
54 | 15 | $166.53 | laser | Male | South Africa | 50 | 1 |
55 | 15 | $253.02 | diners-club-carte-blanche | Female | Canada | 39 | 2 |
56 | 16 | $193.56 | americanexpress | Female | China | 30 | 2 |
57 | 18 | $80.57 | china-unionpay | Male | Brazil | 30 | 1 |
58 | 18 | $250.29 | jcb | Male | Yemen | 41 | 1 |
59 | 15 | $46.79 | jcb | Female | Japan | 42 | 1 |
60 | 18 | $276.56 | laser | Male | Slovenia | 32 | 2 |
61 | 14 | $135.13 | jcb | Male | Tanzania | 31 | 1 |
62 | 14 | $195.58 | jcb | Female | China | 42 | 1 |
63 | 15 | $182.98 | visa | Female | China | 52 | 2 |
64 | 8 | $221.03 | jcb | Male | Zimbabwe | 29 | 1 |
65 | 3 | $128.11 | jcb | Female | China | 40 | 1 |
66 | 19 | $76.60 | diners-club-carte-blanche | Female | Indonesia | 38 | 1 |
67 | 13 | $27.07 | jcb | Female | China | 59 | 2 |
68 | 4 | $109.20 | diners-club-carte-blanche | Male | Russia | 48 | 2 |
69 | 4 | $276.85 | jcb | Male | Uruguay | 57 | 2 |
70 | 19 | $195.10 | jcb | Male | Sao Tome and Principe | 25 | 1 |
71 | 5 | $112.23 | instapayment | Male | Zambia | 41 | 1 |
72 | 15 | $61.94 | jcb | Female | Nigeria | 41 | 1 |
73 | 4 | $35.08 | jcb | Female | China | 35 | 2 |
74 | 20 | $60.13 | switch | Male | China | 23 | 2 |
75 | 6 | $277.11 | visa-electron | Female | Portugal | 54 | 2 |
76 | 5 | $220.47 | jcb | Female | Russia | 37 | 2 |
77 | 14 | $185.57 | laser | Male | Russia | 53 | 2 |
78 | 19 | $295.96 | diners-club-enroute | Male | Greece | 51 | 1 |
79 | 12 | $238.86 | visa | Female | Indonesia | 45 | 2 |
80 | 3 | $275.81 | visa-electron | Female | Indonesia | 26 | 2 |
81 | 7 | $77.07 | visa | Female | Portugal | 57 | 1 |
82 | 2 | $252.58 | mastercard | Female | Russia | 45 | 2 |
83 | 4 | $134.78 | jcb | Male | Japan | 29 | 1 |
84 | 3 | $43.49 | americanexpress | Male | Indonesia | 48 | 2 |
85 | 1 | $223.78 | jcb | Male | Mexico | 53 | 2 |
86 | 8 | $238.74 | jcb | Female | China | 28 | 2 |
87 | 9 | $291.30 | americanexpress | Male | Togo | 44 | 1 |
88 | 14 | $79.46 | jcb | Female | Finland | 54 | 2 |
89 | 16 | $193.73 | jcb | Male | Indonesia | 57 | 1 |
90 | 13 | $224.23 | visa-electron | Female | Pakistan | 23 | 2 |
91 | 16 | $247.43 | mastercard | Female | Honduras | 27 | 1 |
92 | 9 | $186.11 | jcb | Male | China | 56 | 2 |
93 | 17 | $58.48 | jcb | Male | China | 53 | 2 |
94 | 1 | $281.40 | jcb | Female | Philippines | 46 | 2 |
95 | 10 | $254.37 | bankcard | Male | Brazil | 42 | 1 |
96 | 8 | $145.00 | jcb | Female | Indonesia | 50 | 2 |
97 | 20 | $122.35 | jcb | Female | Sweden | 25 | 2 |
98 | 1 | $210.77 | jcb | Male | Portugal | 50 | 1 |
99 | 7 | $225.37 | diners-club-carte-blanche | Female | South Africa | 43 | 2 |
100 | 18 | $87.98 | maestro | Male | China | 37 | 2 |
Note: | |||||||
Marital Status 1 = Married | |||||||
Marital Status 2 = Single |
Question 1
From given data and by using excel, we have
Sample mean = Xbar = 158.25
Sample standard deviation = S = 83.75
Question 2
Here, we have to find the z-score and their probabilities values by using z-table. Table and calculations are given as below:
Z = (X – mean) / S
Line # |
x value |
z - score |
Value in Z table |
2 |
Low value (L) =$27.07 |
Z = (27.07 –158.25)/83.75 = -1.57 |
0.058635883 |
51 |
Middle Value (M) =$164.71 |
Z = (164.71 – 158.25)/83.75 = 0.077 |
0.530741658 |
101 |
High Value (H) = $295.56 |
Z = (295.56 – 158.25)/83.75 = 1.64 |
0.949447744 |
Question 3
Here, we have to find the values of X = mean + Z*Standard deviation
z – score |
x value |
z = -2.50 |
X = 158.25 – 2.50*83.75 = -51.125 |
z = 3.20 |
X = 158.25 + 3.20*83.75 = 426.25 |
z = 0 |
X = 158.25 + 0*83.75 = 158.25 |
z = 0.5 |
X = 158.25 + 0.5*83.75 = 200.125 |
Question 4
Here, we have to find P(L<X<H)
P(L<X<H) = P(27.07< X< 295.56)
P(L<X<H) = P(X<295.56) – P(X<27.07)
P(L<X<H) = 0.949447744 - 0.058635883
(by using table from question 1)
P(L<X<H) = 0.890812
Required curve is given as below: