Subquery syntax

Hi Experts,

I have a table in SQL Server that represents data imported from a 2-d table with the following structure:

CREATE TABLE [dbo].[masterdata](
	[collectionid] [int] NOT NULL,
	[row] [int] NOT NULL,
	[varname] [nvarchar](50) NOT NULL,
	[group] [int] NOT NULL,
	[vartype] [nvarchar](50) NULL,
	[varvalue] [nvarchar](max) NULL,
 CONSTRAINT [PK_masterdata] PRIMARY KEY CLUSTERED 
(
	[imparcid] ASC,
	[row] ASC,
	[varname] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]

GO

Sample data would be:

The challenge I can't seem to solve is I need to come up with a query that will provide the sum and average for certain other variables from the corresponding collectionid and row in the list based on the values for the varname listed.  So for example there is a dependent variable 'Score1' for which the data would be:

The results of the query I need would be:

I'm sure there is a way to form a subquery to do this but my SQL skills aren't yet up to it.

Thanks,
Deedub