Solve the below problem using Stratified Sampling Method

1. Suppose you want to open a 'book' shop at Dhaka New Market. There are 235 shops currently,r operating in there of which 100 are small and 90 are large. As a beginner, an idea about monthly sell of the existing shops would be useful. Under this circumstance, 16 shops are randome selected from two strata and the total sells (in '000 5) over the last month of the sampled shops are as follows: El: 68 83 62 90 82 81 88 72 61 BE: 107105 135 112 115 108 101 (i) Find an estimate of the monthly sells per shop (ii) Also estimate the standard error of the sample mean