1. suppose a varies jointly with b and c and inversely with d and a = 400 when b = 16, c = 5, and d = 2. write the equation that models the relationship. ( show your work so i know how you got your answer and in advance! )

Can someone answer it, and plot it, for 20 points and brainliest answer? p. s. they're the same ! : )

Weekly wages at a certain factory are normally distributed with a mean of $400 and a standard deviation of $50. find the probability that a worker selected at random makes between $450 and $500

According to a study conducted in 2015, 18% of shoppers said that they prefer to buy generic instead of name-brand products. suppose that in a recent sample of 1500 shoppers, 315 stated that they prefer to buy generic instead of name-brand products. at a 5% significance level, can you conclude that the proportion of all shoppers who currently prefer to buy generic instead of name-brand products is higher than .18? use both the p-value and the critical-value approaches.