I need the right answer

The demand for Carolina Industries' product varies greatly from month to month. Based on the past two years of data, the following probability distribution shows the company's monthly demand: Unit Demand 100 300 400 500 Probability 0.3 0.25 0.15 0.3 If the company places monthly orders qual to the expected value of the monthly demand, what should Carolina's monthly order quantity be for this product? Monthly order quantity units b. Assume that each unit demanded generates s70 in revenue and that each unit ordered costs $60. How much will the company gain or lose in a month if it places an order based on your answer to part (a) and the actual demand for the item is 250 units? For subtractive or negative number use a minus sign. (Example: 300) G. What are the variance and standard deviation for the number of units demanded? 1f required, round your answers to two decimal places Variance Standerd deviation