There is one error in one of five blocks of a program. to find the error, we test three randomly selected blocks. let x be the number of errors in these three blocks. compute e(x) and var(x)

Answer with explanation:

Number of Blocks in the program =5

Number of errors in the Program =1

Probability of an event

Probability of getting an error in a program out of five programs

Now, three programs are selected randomly

Required probability that is Expectation E(x)

        =1 ×Error in first one and No error in last two +2×Error in Second one and No error in first and last +3×Error in Third one and No error first and Second one

→E(x²)

Variance (x)

      =E(x²)-E(x)

, and

for

step-by-step explanation:

we can analyze the pattern at which the terms increase. let us denote , , , so that we can call

note the following:

the pattern: to get the next term value, we just add the next term number (e.g. 1st, 2nd, to the previous term value (term values are the given numbers in the question, 1, 3, 6, 10, 15,

from , to get to , we add

from , to get to , we add

etc.

we need to form a recursive formula, a formula that has the next term as a function of the previous term. so a possible recursive formula can be

, and for

i believe that the answer is

b. y-1=-2(x-4)

hope this !