Personal statement to apply for graduate school with a change in major I live in Vietnam and did a Bachelor of Business (Economics and Finance) from an Australian university, Vietnam campus. I am planning to apply for statistics for graduate study in the US. I have always been in math-specialization classes since I was in grade 3 and I attended the best highschool in my country. However, when choosing undergraduate major, I was not fully advised and chose finance, the hottest career in my country. My family's financial condition back then was also not so great for me to think about studying abroad. However, now my family's financial capacity is much better and I also realize the opportunity in statistics in the US. 

Really appreciate any inputs about how I should present my case so that the admission committee can realize my ability and passion for statistics, especially from someone who has done this before (change major from undergraduate to graduate)
People's interests change.  This doesn't require an explanation.  Here's an example:  I started college unsure whether to major in music or math.  I started out doing both.  It worked great the first semester.

Second semester: I got to my first day of Calculus II a few minutes late, and had to sit in the back.  It was a terrible room, long and narrow, and I felt disconnected from the teacher, and completely lost.  I was a pretty immature 17yo, and decided then and there to drop the class without giving it even a second chance.

Fast forward: I did the music degree, worked in an orchestra job for several years, paid off what I owed a relative for my cello, and went back to school for math and computer science.  I spent a year and a half taking math and CS courses, and got a programming job in my college's IT department.  I found out COBOL was boring, and applied to grad school.

In my personal statement I left out ALL of the above, and talked instead about my interest in combining math and computer science.

I didn't say, If I never play Ravel's Bolero again, it will be once too often.  I didn't say, As a COBOL programmer the closest I got to using my math was calculating GPAs.

Math is the language of science.  Statistics help us make sense of experimental results.  There's plenty of positives about statistics you can talk about in your personal statement.

There is no need to cover whatever meandering route got you to statistics.  All the committee will want to know is whether you are academically prepared for graduate study in statistics, and whether you have the imagination and commitment to do original research.