Suppose the test scores on a final exam are normally distributed with a mean of 74 and a standard deviation of 3. What is the probability that a randomly selected test has a score higher than 77?

We have been given that the test scores on a final exam are normally distributed with a mean of 74 and a standard deviation of 3. We are asked to find the probability that a randomly selected test has a score higher than 77.

First of all, we will find z-score corresponding to sample score 77.

, where,        

z = z-score,

x = Random sample score,

= Mean,

= Standard deviation.

Now we need to find .

We will use formula to find the probability greater than a z-score of 1.

Using normal distribution table, we will get:

Therefore, the probability that a randomly selected test has a score higher than 77 would be 0.15866.

6,250

step-by-step explanation:

to get the area, multiply 360 by 160.(57,600)

to find out how many bags of fertilizer it will take, first figure out how many square feet one bag can hold. divide 1000 by 8(125) to get the unit rate(how many square feet one pound of fertilizer can hold)and multiply it by 50(6250). if i haven't made a mistake, that is the answer.