Christy and Amy both are right.
Further explanation:
Given:
Mr. Pham wrote 2.619 on the board. Christy said the number is two and six hundred nineteen thousandths.
Amy said the number is 2 ones 6 tenths 1 hundredth 9 thousandth.
Calculation:
According to the Christy the number is two and six hundred nineteen thousandths.
The number 2.619 can be written according to the Christy as follows,

In the above calculation the symbol
is used to check that right hand side and left hand side is equal or not.
Therefore, the left hand side and right hand side is equal.
According to Christy the number 2.619 is two and six hundred nineteen thousandths.
Therefore, Christy is correct.
According to the Amy the number is 2 ones 6 tenths 1 hundredth 9 thousandth.
The number 2.619 can be written according to the Amy as follows,

Therefore, the left hand side and right hand side is equal.
According to Amy the number 2.619 is 2 ones 6 tenths 1 hundredth 9 thousandth.
Thus, Amy is correct.
Learn more:
1. Learn more about problem on function brainly.com/question/1632445
2. Learn more about problem on triangle brainly.com/question/7437053
3. Learn more about problem on range and domain of functions brainly.com/question/3412497
Answer details:
Grade: Middle school
Subject: Mathematics
Chapter: Numbers
Keywords:
Mr. Pham, Christy, Amy, hundredths, thousandths, nineteen, right hand side, left hand side.