Error CS0266 with my clicker game

I have this issue with this one script and get the UpgradeManager.cs(19,31): error CS0266: Cannot implicitly convert type float to int. An explicit conversion exists (are you missing a cast?) I can't see where I'm trying to convert these two types and I'm not trying to. But any help would be appreciated as I looked around and all the errors that people have is based on animation or transforming things etc not this. EDIT: using Unity 5.0.0f4

 using UnityEngine;
 using System.Collections;
 
 public class UpgradeManager : MonoBehaviour {
     public Click click;
     public UnityEngine.UI.Text itemInfo;
     public float cost;
     public int count = 0;
     public int clickPower;
     public string itemName;
     private float _newCost;
 
     void Update(){
         itemInfo.text = itemName = "\nCost: " + cost + "\nPower: +" + clickPower;
     }
 
     public void PurchasedUpgrade(){
         if (click.gold >= cost) {
             click.gold -= cost;
             count += 1;
             click.goldperclick += clickPower;
             cost = Mathf.Round (cost * 1.15f);
             _newCost = Mathf.Pow (cost, _newCost = cost);
         }
     }
 }