GadRev is a rm that reviews different latest gadgets through a team of four reviewers (R1, R2, R3, and R4). Recently the reviewers reviewed four different tech gadgets (A, B, C, and D) on a scale of 1 to 5 (all integer values) where 1 denotes poor and 5 denotes excellent. These review ratings were then tabulated. However, due to a technical glitch, some of these ratings got deleted. The average rating given by each reviewer, and the average rating given to each gadget were earlier communicated to the team management in a separate email and hence can be useful to retrieve the deleted ratings. The available ratings along with the average ratings are represented in the following table:
To determine which rating provided by Reviewer R1 to Gadget A can help in determining the remaining ratings uniquely, we need to analyze the provided incomplete data matrix and use the given averages.
| Gadget | Reviewer R1 | Reviewer R2 | Reviewer R3 | Reviewer R4 | Average Rating |
|---|---|---|---|---|---|
| A | ? | 3 | 4 | 2 | ? |
| B | 4 | ? | ? | 5 | 4 |
| C | 2 | 5 | ? | ? | ? |
| D | 5 | ? | 3 | 4 | ? |
| Average Rating | ? | 4 | ? | ? |
To find the missing rating for R1 on Gadget A that can uniquely determine the rest, let's apply the following logic:
Given that the average for Gadget B is 4:
By following similar deduction methods for C and D, and considering all constraints:
Therefore, giving a rating of 5 by R1 to Gadget A yields stability across the matrix such that other ratings become determinable.
Correct answer: The rating provided by Reviewer R1 to Gadget A should be 5. This allows determination of the remaining ratings uniquely.
| Reviewer | Gadget A | Gadget B | Gadget C | Gadget D | Average |
|---|---|---|---|---|---|
| R1 | 4 | - | 3 | 5 | 4.0 |
| R2 | 3 | x | 4 | 4 | 3.75 |
| R3 | - | - | - | - | - |
| R4 | 4 | 5 | - | 3 | - |
| Average | 3.67 | 4.00 | - | - |
To solve this problem, we need to determine the missing ratings using the given average ratings for each reviewer and each gadget. Let's consider the provided information and follow the steps below:
Let's break this down step-by-step:
| Reviewer/Gadget | A | B | C | D | Average |
|---|---|---|---|---|---|
| R1 | 2 | - | - | 4 | 3 |
| R2 | - | 3 | 3 | - | 3 |
| R3 | - | - | 3 | 5 | 4 |
| R4 | 5 | - | 2 | - | 4 |
| Avg | 3.5 | 3 | 3 | 4.5 |
Thus, the number of different valid combinations of the missing ratings is 4.




