Answer:
385
Step-by-step explanation:
Answer:
Step-by-step explanation:
Since the length of time taken on the SAT for a group of students is normally distributed, we would apply the formula for normal distribution which is expressed as
z = (x - u)/s
Where
x = length of time
u = mean time
s = standard deviation
From the information given,
u = 2.5 hours
s = 0.25 hours
We want to find the probability that the sample mean is between two hours and three hours.. It is expressed as
P(2 lesser than or equal to x lesser than or equal to 3)
For x = 2,
z = (2 - 2.5)/0.25 = - 2
Looking at the normal distribution table, the probability corresponding to the z score is 0.02275
For x = 3,
z = (3 - 2.5)/0.25 = 2
Looking at the normal distribution table, the probability corresponding to the z score is 0.97725
P(2 lesser than or equal to x lesser than or equal to 3)
= 0.97725 - 0.02275 = 0.9545
Answer:
97
Step-by-step explanation:
For this equation we have to plug in, so z= 6 and w=7. the question is 8z+7w
so plug in 6 for z and 7 for w. 8(6)+7(7) so 8*6 is 48 and 7*7= 49. 48+49= 97
hope this helps :)
Answer:
76
Step-by-step explanation:
4^2 x 5^2 - 18^2
PEMDAS is our acronym for order of operations: Parentheses, exponents, multiplication, division, addition, subtraction.
Since we have no parentheses, we'll calculate the numbers and exponents (PEMDAS) first. "to the power of 2" is also called "squared" and means multiplying that number by itself.
(4x4) x (5x5) - (18x 18)
=16 x 25 - 324
Now we multiply: (PEMDAS)
= 400 - 324
then subtract: (PEMDAS)
=76
