Answer:
Cross-sectional study.
Step-by-step explanation:
- In a cross-sectional study, data are observed, measured, and collected at one point in time.
- In a prospective (or longitudinal) study, data are collected in the future from
groups sharing common factors.
- In a retrospective (or case-control) study, data are collected from the past by going
back in tirme (through exanmination of records, interviews, arıd so on).
Hope this Helps!!

common difference is
3.6 - 5.8 = -2.2
let T1 = 5.8
T2 = 3.6
assuming we are to find T2
T2 = T(2-1) -2.2
= T1 -22
= 5.8 -2.2
= 3.6
To isolate a variable you have to “do something to both sides”. i dont know your equation. but you either have to add, subtract, multiply or divide