Nt1310 Unit 1 Case Study
Homework 4.3 #21
43% of adults in the US receive fewer than 5 phone calls a day. In a random sample of 7 adults, what is the probability that the number receiving fewer than five calls a day is (a) exactly 3 (b) at least 3 (c) more than 3?
n p 7 0.43 x P(Exactly x) P(At most x) P(At least x)
0 0.0195 0.0195 1.0000
1 0.1032 0.1228 0.9805
2 0.2336 0.3564 0.8772
3 0.2937 0.6502 0.6436
4 0.2216 0.8718 0.3498
5 0.1003 0.9721 0.1282
6 0.0252 0.9973 0.0279
7 0.0027 1.0000 0.0027
I plugged in the given percentage of adults (43%) into the “p” section of the table and the random sample size into the “n” section of the table and hit enter to have excel do the calculations.
In a random sample of 7 adults, the probability of the number of adults receiving fewer than five calls a day being exactly 3 is 29.37%. …show more content…
In a random sample of 7 adults, the probability of the number of adults receiving fewer than five calls a day being at least 3 is 64.36%.
In a random sample of 7 adults, the probability of the number of adults receiving fewer than five calls a day being more than 3 is
34.98%.
TCO #5: Given a business situation word problem or case study such as defective items or waiting in lines, use discrete probability concepts to determine a course of action.
An example of this TCO was covered in our "Contingency Table" tutorial found in our Week 3 Lecture:
A manufacturer of bicycles holds a surprise quality audit of two identical production lines. All bicycles assembled during a randomly selected one hour period are inspected. Line A has 100 bicycles inspected and Line B has 150 inspected. From Line A, the audit finds 29 bicycles with some type of defect, while Line B has 132 non-defective bicycles.
• If a bicycle is randomly selected from all those inspected, what is the probability it is defective?
• If a bicycle is defective, what is the probability it is from Line A?
• If a bicycle is from Line B, what is the probability it is defective?
• Is the defective rate independent of which line produced the bicycle?
LINE DEFECTIVE NOT DEFECTIVE TOTAL
A 29 71 100
B 18 132 150
TOTAL 47 203 250 47/250 0.188 18.80%
29/47 0.617021 61.70%
18/150 0.12 12% Defective is not independent of the line
43% of adults in the US receive fewer than 5 phone calls a day. In a random sample of 7 adults, what is the probability that the number receiving fewer than five calls a day is (a) exactly 3 (b) at least 3 (c) more than 3?
n p 7 0.43 x P(Exactly x) P(At most x) P(At least x)
0 0.0195 0.0195 1.0000
1 0.1032 0.1228 0.9805
2 0.2336 0.3564 0.8772
3 0.2937 0.6502 0.6436
4 0.2216 0.8718 0.3498
5 0.1003 0.9721 0.1282
6 0.0252 0.9973 0.0279
7 0.0027 1.0000 0.0027
I plugged in the given percentage of adults (43%) into the “p” section of the table and the random sample size into the “n” section of the table and hit enter to have excel do the calculations.
In a random sample of 7 adults, the probability of the number of adults receiving fewer than five calls a day being exactly 3 is 29.37%. …show more content…
In a random sample of 7 adults, the probability of the number of adults receiving fewer than five calls a day being at least 3 is 64.36%.
In a random sample of 7 adults, the probability of the number of adults receiving fewer than five calls a day being more than 3 is
34.98%.
TCO #5: Given a business situation word problem or case study such as defective items or waiting in lines, use discrete probability concepts to determine a course of action.
An example of this TCO was covered in our "Contingency Table" tutorial found in our Week 3 Lecture:
A manufacturer of bicycles holds a surprise quality audit of two identical production lines. All bicycles assembled during a randomly selected one hour period are inspected. Line A has 100 bicycles inspected and Line B has 150 inspected. From Line A, the audit finds 29 bicycles with some type of defect, while Line B has 132 non-defective bicycles.
• If a bicycle is randomly selected from all those inspected, what is the probability it is defective?
• If a bicycle is defective, what is the probability it is from Line A?
• If a bicycle is from Line B, what is the probability it is defective?
• Is the defective rate independent of which line produced the bicycle?
LINE DEFECTIVE NOT DEFECTIVE TOTAL
A 29 71 100
B 18 132 150
TOTAL 47 203 250 47/250 0.188 18.80%
29/47 0.617021 61.70%
18/150 0.12 12% Defective is not independent of the line