Nielsen interview questions

For some reason I was interviewed first and then they decided I needed to come in to do the analytical assessment. This is very different to what some other applicants described here. And it feels like I put so much effort into passing the interviews and now some test will determine if I get the job or not

I have applied online, in a month I've got email and scheduled phone call with lady from HR department (screening). This conversation was quick and easy, few behavioral question. Then in a week I've got another phone interview with my prospective supervisor. He asked about my experience, education. In addition, he checked my conceptual understanding of some statistical techniques. In a week i have got email informing about their intention to proceed with in -person interview (meeting with management and assessment test , it suppose to be long enough) . I have asked to schedule it ASAP because I've got an offer from another company, and had to think quickly. They respond me in 2 weeks, I have started in new company. I was actively seeking for work and 6 weeks was just too much for me