Whats the equation????

Question

here is the word problem please help me figure out what the equation looks like if someone can show me the equation I can figure out the rest.

A principal of $5000 was invested in a savings account for 4 years. If the intrest earned for the period was $400, waht was the intrest rate?

Answer 1

the equation for interest is I=p*r*t

so plug in 400 for I, 5000 for P and 4 for T(time) in years:

400=5000*r*4

then you just solve for R


hope that helped

Answer 2

5400 = 5000*(1+x)^4