Which of the following statements is true?

1.75 = 1 4/3

3 9/20 = 3.45

7/8 = 0.78

700 = 7/100

3 9/20 = 3.45 is the correct statement.

Let's look at each answer choice to determine if it is true or false.

Choice 1: The first choice states that 1.75 = 1 4/3. Let's change 1.75 into a fraction and see if it is truly 1 4/3. (x will be the fraction)

1.75 = x

175 = 100x

175/100 = x

7/4 = x

1 3/4 = x

Clearly, Choice 1 is incorrect.

Choice 2: Choice 2 states that 3 9/20 = 3.45. Let's change 3.45 to a fraction and see if it is 3 9/20. (g will be our fraction)

3.45 = g

345 = 100g

345/100 = g

69/20 = g

3 9/20 = g

Choice 2 is in fact correct.

Choice 3: Choice 3 states that 7/8 is equal to 0.78 Let's convert 0.78 to a fraction and see if it is really 7/8. (q will be our fraction)

0.78 = q

78 = 100q

78/100 = q

39/50 = q

This fraction cannot be simplified any further. Thus, Choice 3 is false.

Choice 4: Choice 4 claims that 700 is equal to 7/100. Let's test this by converting 700 into a fraction and checking if they are equal. (t will be our fraction)

700 = t

70000 = 100t

700/1 = t

This fraction cannot be simplified any further. Thus, this choice is also incorrect.

Based on our results, Choice 2 is true.