The time until failure for an electronic switch has an exponential distribution with an average time to failure of 2 years, so that λ = 1 2 = 0.5. (Round your answers to four decimal places.) (a) What is the probability that this type of switch fails before year 1?

just took the test and my answers down below!

step-by-step explanation:

check the pic :

i believe a. 12x≥120 is the answer

proportions are fractions that equal to each other. so if two fractions are the same, they are proportional.

let's check the answers to see if they are proportional.

question a is not proportional because you can't turn 1.5/3 to 3/9. if you try to multiply 1.5/3 by 2 or 3, you wont get 3/9. it's impossible to make the fractions the same.

question b is not proportional because you can't turn 22/33 to 4/6. 33 can't go into 6.

question c is proportional because when you multiply 2 and 3 by 71, you would get 142/213, and those fractions equal to each other

question d is proportional because when you divide 14 and 7 by 2, you would end up with 7/3.5, and those fractions equal to each other.