Matrix Missing Number
1. The problem is to find the missing number represented by ? in the matrix:
$$\begin{matrix}7 & ? & 108 \\ 8 & 12 & 96 \\ 9 & 132 & 84\end{matrix}$$
2. Let's analyze the pattern in each row.
- Row 2: 8, 12, 96
Check if the product of the first two numbers relates to the third:
$$8 \times 12 = 96$$, matching the third number.
- Row 3: 9, 132, 84
Check product of first two numbers:
$$9 \times 132 = 1188$$, which does not equal 84.
Let's check division:
$$132 \div 9 = 14.67\ldots$$
$$84 \div 132 = 0.636\ldots$$
No straightforward pattern there.
3. Let's check the products of the second and third numbers in the rows:
- Row 1: ? and 108
- Row 2: 12 and 96
- Row 3: 132 and 84
Investigate relationship between first and product of last two numbers:
- Row 2:
$$12 \times 96 = 1152$$
$$1152 \div 8 = 144$$
- Row 3:
$$132 \times 84 = 11088$$
$$11088 \div 9 = 1232$$
- Row 1:
Let ? = x
$$x \times 108 = y$$
To find if y divided by 7 fits a pattern.
Looking at these, maybe no clear pattern here, let's try sums.
4. Check sums before and after:
- Row 2 sum:
$$8 + 12 = 20$$
The third number is 96, no relation with 20.
- Row 3 sum:
$$9 + 132 = 141$$
Third number is 84.
No clear product or sum pattern.
5. Check columns for patterns:
- Column 1: 7, 8, 9
- Column 2: ?, 12, 132
- Column 3: 108, 96, 84
Notice that column 3 numbers decrease by 12 each row:
$$108 - 12 = 96$$
$$96 - 12 = 84$$
Maybe column 2 is increasing similar way:
From 12 to 132 increased by 120.
If ? follows a pattern starting with 12 and jumps 120, maybe ? is -108 (12 - 120), but this is negative and unlikely.
6. Check ratio in column 3:
$$108 \div 7 = 15.43$$
$$96 \div 8 = 12$$
$$84 \div 9 = 9.33$$
No clear sequence.
7. Let's check if multiplication of column 1 and column 2 equals column 3:
- Row 2:
$$8 \times 12 = 96$$ correct.
- Row 3:
$$9 \times 132 = 1188$$ which is not 84.
So this doesn't hold.
8. Let's try multiplying column 1 by column 3 and dividing by column 2:
- Row 2:
$$8 \times 96 \div 12 = 64$$
- Row 3:
$$9 \times 84 \div 132 = 5.73$$
No clear pattern.
9. Alternatively, observe column 2 entries:
12 and 132, possibly related by factor 11 (12 x 11 = 132).
Try applying factor 11 again to find ?:
If 7 x 11 = 77, so possibly ? = 77.
Test row 1 with ?=77:
Check if 7 x 77 = 108, no (7 x 77 = 539).
But row 2 8 x 12 = 96 holds.
No conclusive pattern.
10. Considering the consistency in Row 2, where 8 x 12 = 96.
Assuming similar for Row 1, 7 x ? = 108.
Solve for ?:
$$? = \frac{108}{7} = 15.43$$
Since ? is likely an integer, check for nearest integer:
Check 15 x 7 = 105 (close to 108).
Check 16 x 7 = 112 (also close).
Given lack of other patterns, the most reasonable answer is:
$$\boxed{15.43}$$
or approximately 15.
Hence the missing number ? is approximately 15.43.