The number of years from 1985 to 1994 is 9 years.
To calculate the number of subscribers in 1994, we can use the formula for exponential growth. Since the number of subscribers increases by 75% each year, we can express this growth as follows:
\[ N(t) = N_0 \times (1 + r)^t \]
Where:
- \( N(t) \) is the number of subscribers at time \( t \),
- \( N_0 \) is the initial number of subscribers (285),
- \( r \) is the growth rate (75% or 0.75),
- \( t \) is the number of years (9).
Plugging in the values:
\[ N(9) = 285 \times (1 + 0.75)^9 \]
Calculating \( (1 + 0.75) \):
\[ 1 + 0.75 = 1.75 \]
Now raise 1.75 to the power of 9:
\[ 1.75^9 \approx 33.4132 \]
Now multiply by the initial number of subscribers:
\[ N(9) = 285 \times 33.4132 \approx 9512.282 \]
Rounding to the nearest whole number, the estimated number of subscribers in 1994 is approximately:
\[ \boxed{9512} \]