I need to write R functions for the following:

1. Maximum value of the probability density function of N (-4,25) distribution (mean=-4, sd=5)

This one i know to use dnorm (x, mean=-4, sd=5). I'm not sure what to plug in for x

Next question .

scores are distributed as N(174, 31.2^2) random variable (sd=31.2)

Paul needs to score better than 76% of the candidates on the test. Write a R command that calculates how many points Paul should have on the test (at least that many) to be certain that she will be admitted.

Another part related to scores questions - Write a R command that calculates the probability that Paul will score at least 221 points.