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
Answer:
The proof is below
Step-by-step explanation:
Given a parallelogram ABCD. Diagonals AC and BD intersect at E. We have to prove that AE is congruent to CE and BE is congruent to DE i.e diagonals of a parallelogram bisect each other.
In ΔACD and ΔBEC
AD=BC (∵Opposite sides of a parallelogram are equal)
∠DAC=∠BCE (∵Alternate angles)
∠ADC=∠CBE (∵Alternate angles)
By ASA rule, ΔACD≅ΔBEC
By CPCT(Corresponding Parts of Congruent triangles)
AE=EC and DE=EB
Hence, AE is conruent to CE and BE is congruent to DE
