Exercise 4.6-4: MasterCard records show that credit card purchases for the month
ID: 3353783 • Letter: E
Question
Exercise 4.6-4: MasterCard records show that credit card purchases for the month of December average $1200 with standard deviation $550. Assuming that purchases approximately follow the normal curve
1. What percentage of customers spend between $1000 and $2000 in December using their MasterCard?
2. What percentage of customers will charge less than $2000 for the month of December?
3. Suppose that MasterCard gives special offers to customers who spend more than $1500 in a month. What percentage of customers will “earn” a special offer for their December purchases?
4. How much did a MasterCard customer spend if only 2% of all customers spent more?
Explanation / Answer
1)
2)
3)
~29.27%
4)
for highest 2% ; at 98th percentile z score =2.0537
hence corresponding value =mean +z*std deviation =2329.56 ~ $2330
for normal distribution z score =(X-)/Related Questions
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