Final answer:
It will take approximately 12 months for Yoko to complete her payments.
Step-by-step explanation:
To determine how long it will take Yoko to complete her payments, we need to calculate the total amount spent on the purchases, the monthly interest, and the monthly payment. Yoko bought a computer for $1900, a printer for $300, and a scanner for $180, making the total purchase amount $2380. With a 4% monthly interest, the monthly interest would be 0.04 * 2380 = $95.2. If Yoko pays $100 per month, she would have to cover both the purchase amount and the monthly interest. So her monthly payment would be $100 + $95.2 = $195.2.
To find out how long it takes for her to complete her payments, we can divide the total purchase amount by the monthly payment: 2380 / 195.2 = ~12.20. Therefore, it will take approximately 12 months for Yoko to complete her payments.