Question

In: Statistics and Probability

The goal of this lab is to standardize data, to compute probabilities using the standard normal...

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

Solutions

Expert Solution

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:



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