To predict the total wages using the equation of the trend line \( y = 0.75x + 30 \), we need to substitute \( x \) with the number of phones assembled, which is 100.
Plugging the values into the equation:
\[ y = 0.75(100) + 30 \]
Calculating this step-by-step:
- Calculate \( 0.75 \times 100 = 75 \)
- Add 30 to the result: \( 75 + 30 = 105 \)
Therefore, the total wages for assembling 100 phones in one day would be:
\[ y = 105 \]
Thus, the wages would be $105.00.