Q1) Many natural phenomena which humans observe are about generally distributed. Based on observations, it can be supposed that human intelligence is approximately distributed. Graph below shows comparisons of standard normal scores (z-scores) and IQ scores.
Need help with these
a) If person is selected at random and tested, determine the probability of that person having an IQ score between 85 and 115. Make use of EXCEL to help determine the probability.
P(85 < X < 115): (where X is the IQ score).
b) What IQ score will correspond to 50th percentile. Make use of EXCEL to help determine the percentile. 50th Percentile IQ score: (where X is the IQ score).
c) Use What IQ score will correspond to 85th percentile. Make use of EXCEL to help determine the percentile. 85th Percentile IQ score: (where X is the IQ score).