Problem $6$: $(10$ points$)$

Consider an Intel P$4$ microprocessor with a $16$ Kbyte unified L$1$ cache. The miss rate for this cache is $3\%$ and the hit time is $2$ CCs$.$ The processor also has an $8$ Mbyte, on$-$chip L$2$ cache. $95\%$ of the time, data requests to the L$2$ cache are found. If data is not found in the L$2$ cache, a request is made to a $4$ Gbyte main memory. The time to service a memory request is $100,000CCs.$ On average, it takes $3\mathrm{.}5$ CCs to process a memory request. How often is data found in main memory?