Angelo says that if you know one unit rate in a proportional relationship, the other unit rate is always the multiplicative inverse of the unit rate you know. Is Angelo correct? Explain

if you go 10 miles per hour

then that is indeed 1/10 hour per mile

In general yes
do not divide by zero though :)

Yes, Angelo is correct. In a proportional relationship, the ratio between the two quantities remains constant. This ratio is called the unit rate. It represents the amount of one quantity in relation to one unit of the other quantity.

If you know one unit rate in a proportional relationship, you can find the other unit rate by taking the multiplicative inverse of the known unit rate. The multiplicative inverse of a number is the reciprocal of that number.

For example, let's say in a proportional relationship, the unit rate is 3. This means that for every 1 unit of the first quantity, there are 3 units of the second quantity. Now, to find the other unit rate, we take the multiplicative inverse of 3, which is 1/3. This means that for every 1 unit of the second quantity, there will be 1/3 units of the first quantity.

So, in a proportional relationship, knowing one unit rate allows you to find the other unit rate by taking its multiplicative inverse.