Q54

Consider a demand paging system with four page frames (initially empty) and $\text{LRU}$ page replacement policy. For the following page reference string

$$7, 2, 7, 3, 2, 5, 3, 4, 6, 7, 7, 1, 5, 6, 1$$

the page fault rate, defined as the ratio of number of page faults to the number of memory accesses $\textit{(rounded off to one decimal place)}$ is _____________.