Modify an AppExchange dashboard
Maria Jimenez is looking for reports and dashboards on AppExchange to track her team's transition to Lightning Experience. Install the AppExchange Dashboard Pack for Sales, Marketing and Service package into your Trailhead Playground and make some modifications. 

You’ll need your hands-on org username and password to complete this challenge. If you're using a Trailhead Playground, this article shows you how to find your username and reset your password. If you have trouble installing the package, follow the steps in this article.

In your Trailhead Playground, install the AppExchange Dashboard Pack for Sales, Marketing and Service.
Clone the 1-Account, Contact & Opportunity Data Quality dashboard and name it My Account and Contact Dashboard.
Add a dashboard filter on the Billing City field so that the dashboard only shows info about Accounts in London.
Save and refresh the dashboard.

I am trying to complete this challenge from past 4 hours still am not able to do it. Please help me guys! Guide me!!!!

I receive this error when I check my challenge.


Challenge not yet complete... here's what's wrong: 
An account with a related opportunity did not calculate the correct potential value.

The task was to Create a rollup summary field that determines the potential value of the opportunities associated with an account.
Add a custom field to the standard account object that provides a rollup summary of the total expected revenue from all related opportunities.The rollup summary field should be labeled 'Potential Value' and have the Field Name of 'Potential_Value'. The resulting API name should be 'Potential_Value__c'.
The rollup summary should calculate the total expected revenue of all the opportunities related to the account.

Here is a snap shot of my work. Any suggestions as to why this is failing?



Thanks,
Darren