Scores on a english test have average of 85 with standard deviation of 8. what is the probabilty of a student scoring less than 77 on the test? write your answer as a percent.

47.725%

If the mean (μ) is 80, and the standard deviation (σ) is 5, then all scores between 80 and 90 would fall between 0 and 2 standard deviations above the mean.

Using the equation for Z score (Z = (X-μ)/σ) for each X value (80 and 90) then the Z scores are 0 and 2, respectively.  

Using a normal distribution table, it can be found that P(80 < z) = .5 (this is the probability that a random score would be greater than 80.  It makes sense that it is .5 or 50% because 80 is the mean.)

And the P(90 > z) = .97725.  (this is the probability that a random score would be less than 90.)

10

Step-by-step explanation:

3

step-by-step explanation:

in standard form:

a= dictionaries

b= maps

you have to buy 3 dictionaries, so put a 3 next to the a (dictionaries) so that you can multiply them by each other.

a3+b= 60 (the amount of money you have)

we already know the cost of a=15 so replace a with $15

($15 x 3)+b=60

multiply 15 and 3 to get $45 and replace it with $45

45+b=60

and then replace b with 15 to get the total:

45+15=60

that means you have $15 left after buying 3 dictionaries.

15 divided by the cost of a map ($5) equals 3.

so you can buy 3 maps.

sorry if it was confusing!