Solution:
To calculate the tax charged, we can multiply the cost of the telephone ($414) by the sales tax rate (3% or 0.03):

Tax charged = $414 * 0.03 = $12.42
Total price = $414 + $12.42 = $426.42

Rounding to the nearest cent, the total price is $426.42.

Solution to convert the fraction 15/16 to a percentage:

Step 1: Divide the numerator (15) by the denominator (16): 15 ÷ 16 = 0.9375
Step 2: Multiply the result by 100 to convert it to a percentage: 0.9375 × 100 = 93.75%

So, the equivalent percentage of 15/16 is 93.75%.

Solution to convert the fraction 59/100 to a percentage:

Step 1: Divide the numerator (59) by the denominator (100): 59 ÷ 100 = 0.59
Step 2: Multiply the result by 100 to convert it to a percentage: 0.59 × 100 = 59%

So, the equivalent percentage of 59/100 is 59%.

The formula for compound interest is A = P(1 + r/n)^(nt), where:
- A represents the final amount or accumulated value.
- P represents the principal amount or initial investment.
- r represents the annual interest rate (expressed as a decimal).
- n represents the number of times interest is compounded per year.
- t represents the number of years the money is invested for.

9 2/3 - 6 1/2 = 3 1/6

9 4/6 - 6 3/6 = 3 1/6