Answer:
12rf
Step-by-step explanation:
4 times 3 is 12 and r times f just becomes rf so you are correct.
16-~7 make sure to leave the power 5 out
Answer:
This indicates that the chances of the mean life span today is greater than 70 years is 0.5871
Step-by-step explanation:
The past year showed an average life span of 71.8 years.

Population standard deviation = 8.9 years

We are supposed to find the mean life span today is greater than 70 years
i.e. P(X>70)
Formula : 

Z=−0.202
P(X<70)=0.4129
P(X>70)=1-P(X<70)=1-0.4129=0.5871
Hence This indicates that the chances of the mean life span today is greater than 70 years is 0.5871
86% written as a fraction is 43/50
The answer is B)<span>Steven earned $820 more in interest in his account than Evan.</span>