Find the quotient. \[ -\frac{3}{8} \div\left(-\frac{2}{3}\right)= \]

Step 1 ：The problem is to find the quotient of \(-\frac{3}{8} \div \left(-\frac{2}{3}\right)\).

Step 2 ：The division of two fractions can be solved by multiplying the first fraction by the reciprocal of the second fraction. The reciprocal of a fraction is obtained by swapping its numerator and denominator.

Step 3 ：Also, the division of two negative numbers results in a positive number. So, we need to multiply -3/8 by -3/2.

Step 4 ：Performing the multiplication gives us a quotient of 0.5625.

Step 5 ：Final Answer: The quotient of \(-\frac{3}{8} \div \left(-\frac{2}{3}\right)\) is \(\boxed{0.5625}\).