Q:

NSMutableArray.  Object value is not being replaced

I have a NSMutableArray and I want to change the value of a particular object. 
However, it's not changing. 
Below is my code:
//create two array to store data later
NSMutableArray *feelingsArray = [[NSMutableArray alloc] init];

// get paths from root direcory

NSArray *paths = NSSearchPathForDirectoriesInDomains (NSDocumentDirectory, NSUserDomainMask, YES);

// get documents path

NSString *documentsPath = [paths objectAtIndex:0];

// get the path to our Data/plist file

NSString *feelingsPath = [documentsPath stringByAppendingPathComponent:@"Feeling.plist"];

//This copies objects of plist to array if there is one
[feelingsArray addObjectsFromArray:[NSArray arrayWithContentsOfFile:feelingsPath]];

//replace object at particular location
[datesArray replaceObjectAtIndex:number withObject:feeling.text];

Do I need to make any changes or add some code like synchronise etc.? 
Please provide some guidance. 

A:

Shouldn't
[datesArray replaceObjectAtIndex:number withObject:feeling.text];

be
[feelingsArray replaceObjectAtIndex:number withObject:feeling.text];

?