(a) Consider the Excel functions: =STDEV( number 1,[ number 2],) and: = STDEV.P (number 1 , [number2], ..). i. Explain the difference between these two Excel functions. (3 marks) ii. Provide a real business example when each function would be appropriate (i.e. one example for each function). (4 marks) (b) A factor input used in a company's production process costs $6.50 per unit. Weekly internal demand (in hundreds) for the factor is uncertain, but is assumed to have the following probability distribution: i. Calculate the expected weekly cost of the factor input. (4 marks) ii. Based on the above Excel worksheet, write an Excel function which would return the standard deviation of the weekly demand of the factor input (in hundreds), explaining why the function works. (5 marks) (c) Arrivals at a busy photo booth are assumed to follow a Poisson distribution with =0.5 per minute. i. Write an Excel function which would return the probability that the time to arrival of the next person is less than one minute, explaining why the function works. (5 marks) ii. If X is the time to arrival of the next person (in minutes), write an Excel function which would return: P(X>2.5X>1) (4 marks) (a) Consider the Excel functions: =STDEV( number 1,[ number 2],) and: = STDEV.P (number 1 , [number2], ..). i. Explain the difference between these two Excel functions. (3 marks) ii. Provide a real business example when each function would be appropriate (i.e. one example for each function). (4 marks) (b) A factor input used in a company's production process costs $6.50 per unit. Weekly internal demand (in hundreds) for the factor is uncertain, but is assumed to have the following probability distribution: i. Calculate the expected weekly cost of the factor input. (4 marks) ii. Based on the above Excel worksheet, write an Excel function which would return the standard deviation of the weekly demand of the factor input (in hundreds), explaining why the function works. (5 marks) (c) Arrivals at a busy photo booth are assumed to follow a Poisson distribution with =0.5 per minute. i. Write an Excel function which would return the probability that the time to arrival of the next person is less than one minute, explaining why the function works. (5 marks) ii. If X is the time to arrival of the next person (in minutes), write an Excel function which would return: P(X>2.5X>1) (4 marks)