NMIMS – Decision Science
NMIMS MBA Decision Science Solved Assignment
Q 1: Bad gums may mean a bad mood. Researchers discovered that 85% of people who have suffered a bad mood had periodontal disease, an inflammation of the gums. Only 29% of healthy people have this disease. Suppose that in a certain community bad moods are quite rare, occurring with only 10% probability. If someone has periodontal disease, what is the probability that he or she will have a bad mood?
Note: Draw the tree diagram for the above problem. Handwritten tree diagram is prohibited.
Q 2: Using MS-EXCEL show the Regression model, consider ‘Instagram followers’ as dependent variable and ‘no f post per day’ as an independent variable.
Write the interpretation of EXCEL Tables.
Write the conclusion on the fitting of your model also.
| No of followers | No of post per day |
| 439 | 2 |
| 340 | 1 |
| 315 | 4 |
| 444 | 5 |
| 377 | 2 |
| 456 | 5 |
| 495 | 2 |
| 304 | 2 |
| 401 | 5 |
| 305 | 5 |
| 338 | 4 |
| 348 | 2 |
| 402 | 1 |
| 395 | 5 |
Q 3A): 1000 light bulbs with a mean life of 120 days are installed in a new factory and their length of life is normally distributed with standard deviation of 20 days.
If it is decided to replace all the bulbs together, what interval should be allowed between replacements if not more than 10% should expire before replacement?
Note: You are not supposed to use EXCEL or any other software to write this answer.
Q 3B): calculate the average age of migrants for both the categories of gender and write your interpretation.
| Age group | Male | Female |
| 0-4 | 98,34,738 | 91,27,975 |
| 5-9 | 1,09,59,506 | 99,58,059 |
| 10-14 | 1,24,25,108 | 1,14,51,227 |
| 15-19 | 1,26,83,733 | 1,65,18,666 |
| 20-24 | 1,31,97,283 | 3,36,58,466 |
| 25-29 | 1,30,45,214 | 3,75,22,017 |
| 30-34 | 1,21,34,009 | 3,42,86,096 |
| 35-39 | 1,20,60,030 | 3,30,54,887 |
| 40-44 | 1,09,00,143 | 2,72,61,236 |
| 45-49 | 97,04,026 | 2,34,47,716 |
| 50-54 | 79,40,152 | 1,78,42,986 |
| 55-59 | 61,61,754 | 1,51,92,910 |
| 60-64 | 54,01,736 | 1,43,47,372 |
| 65-69 | 36,87,082 | 1,01,41,196 |
| 70-74 | 26,62,421 | 70,33,728 |
| 75-79 | 13,41,572 | 34,93,001 |
| 80-85 | 14,61,296 | 42,53,695 |
Note: You are not supposed to use EXCEL or any other software to write this answer