Q 1 Edward Medical Corporation is working on a machine. Medical standards require that the machine must have the hourly flow, 5 liters 0.1 liter, 90% of the time. On testing the prototype, it is found that 68% of the time, the hourly flow is within 0.07 liter of 5.02. Does the prototype satisfy the medical standards?

Q 2 An architect is designing the interior doors in a men's gymnasium. He wants to make them high enough so that 90% of the men using the doors will have at least half foot clearance. Assuming that the heights will be normally distributed with a mean of 70 inches and a standard deviation of 3 inches, how high must the architect make the doors?

Q3 In a college, marks obtained by students is normally distributed. The number of students getting 70% or more marks is 50,while the number of students getting less than 40% marks is 100 .Find the mean and standard deviation if the total number of candidates appearing is 500.