Recall that an exponential function, with a horizontal asymptote of $y=0$, can be in the form $y=a\times b^x$ where a is the initial value and $b$ is the multiplier. For each part below, determine the initial value, the multiplier, and the time units in each of the following situations.  

1. Bread costs $\$1.87$ now and is increasing in price by $2\%$ each month.

   Answer (a):

   Initial value $=\$1.87$, multiplier $=1+0.02=1.02$ , time is in months.

2. A car is worth $\$12000$ now and is depreciating in value by $12\%$ each year.

   Hint (b):

   Multiplier will be down $0.12$ from $1.0$.

3. Bacteria grow at a rate of $30\%$ every hour. There are currently $1000$.

4. A $\$5000$ investment earns $1\%$ interest every month.