A diamond weighs `3.71 g`. It is put into a box weighing `1.4 kg`. Find the total weight of the box and diamond to the correct number of significant figures.

Explanation

To find the total weight of the box and the diamond, we will follow these steps:

### Step 1: Convert the weight of the diamond to kilograms
The weight of the diamond is given as 3.71 grams. To convert this to kilograms, we use the conversion factor that 1 kg = 1000 g.

\[ \text{Weight of diamond in kg} = \frac{3.71 \, \text{g}}{1000} = 0.00371 \, \text{kg} \]

### Step 2: Identify the weight of the box
The weight of the box is given as 1.4 kg.

### Step 3: Add the weights of the diamond and the box
Now we will add the weight of the diamond (0.00371 kg) to the weight of the box (1.4 kg).

\[ \text{Total weight} = \text{Weight of box} + \text{Weight of diamond} \]
\[ \text{Total weight} = 1.4 \, \text{kg} + 0.00371 \, \text{kg} \]
\[ \text{Total weight} = 1.40371 \, \text{kg} \]

### Step 4: Determine the correct number of significant figures
When adding numbers, the result should be reported to the least number of decimal places of any number in the operation. The weight of the box (1.4 kg) has one decimal place, while the weight of the diamond (0.00371 kg) has five decimal places. Therefore, we round the total weight to one decimal place.

\[ \text{Total weight rounded} = 1.4 \, \text{kg} \]

### Final Answer
The total weight of the box and diamond is **1.4 kg**.

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