18. Suppose that the distribution of scores on the Graduate Record Exam (GRE) isapproximate/y Hormal, with a meun of \( 11=1 \) and an standard deviation of \( a=5 . \) For the population of students who have taken the GRE: 4. What proportion have GRE ncores less than 145 ? b. What poportion howe Gite scores greater than 1577 f.. What is the mimimum CRRK score necuded ti be in the lighast 20 b of the population? d.1fs Mrathate school accepts only studente from the top \( 10 \% 0 \) of the GRR distribcriod, what is the munimum CRE score necded to be accented? 19. Au umportunt reasen that stadents strugele in edllego is that they are soretime onaware that they have notyel mastered a new saik. Strughting students ormnoverestimate their houel of maxferyin