To save for retirement, karla harby put $475 each month into an ordinary annuity for 19 years. interest was compounded monthly. at the end of the 19 years, the annuity was worth $234 comma 341. what annual interest rate did she receive?

Annual interest will be 33.036 %

Explanation:

We have given initial amount P = $475

Time t = 19 years

As interest is compounded monthly

So number of period = 19×12 = 228 period

Final amount is given A = $234341

Amount is given by

%

Annual interest = 12×2.753 =33.036 %

ans.

heterothermic organisms include those organisms that can switch between homeothermic (having body temperature higher than environment) and poikilothermic (having variation in internal body temperature) strategies.

some migratory birds show heterothermy as they decrease their metabolic rate during cold nights to keep their body temperature low. drop in metabolic rate allows increase in production efficiency of birds that reduces the internal body temperature to make it equal to external cold temperature during cold nights.

thus, the correct answer is 'birds allow their temperature drop in order to increase their production efficiency.'