Answer is given below 
Step-by-step explanation:
the index of the string "noisy" 
and 
substringIndex with the index is express as here given below
when we update with replace wiseProverb as "noisy" with "squeaky" 
than 
var wiseProverb = "The noisy wheel gets the grease.";
var substringIndex = 0;
substringIndex = wiseProverb.indexOf("noisy"); 
wiseProverb.replace("noisy", "squeaky");