The question is stated in the pic below

(u) at "985! 4 are compliant. 2. Many industrial structural failures are believed to be the result of crack growth. In most cases, the cracks grow slowly. It is only when the cracks reach intolerable proportions and still go undetected that catastrophe can occur. in a cement wall, occasional hairline cracks are normal and the wall is considered safe when the cracks are not too close together. However, if a number of cracks group together, there may be trouble. Suppose that a given cement wall is considered safe if hairline cracks are evenly spread out and occur on the average of 4.2 cracks per g-foot section of the wall. a. [0-4] What is a suitable probability distribution model in this case? Justify your choice. Use google-sheet le to construct probability distribution and histogram. b. [T-4] Use proper notation and formula to evaluate the probabilities that in a m-foot section of safe wall there are (i) exactly four (evenly spread out) hairline cracks; I} (ii) at most four (evenly spread out) hairline cracks