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:
I believe the answer would be 186
Step-by-step explanation:
241-55=186
3x+7y=-6 -7x+3y=26 -4x+4y=-32 +4x on both sides and you end up with 4y=-32+4x now divide both sides by 4 and you get y=-8+x then to incorporate that in one of the problems 3x+7(-8+x)=-6 do the distributive property with the 7 into the () and you get 3x-56+7x=-6 now add all common variables and get 10x-56=-6 now add 56 to both sides and you get 10x=50 now divide by 10 on both side and you get x=5 now for getting y to equal a number instead of an equation 3(5)+7y=-6 15+7y=-6 subtract 15 on both sides to get 7y=-21 not divide by 7 on both sides to get y=-3 your answers are y=-3 and x=5
Answer:
• for x = 2a√t, make t the subject:
• then find y:
