Answer:
might wanna take a picture instead...
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:
answer is first option
wherein, a = 1, b = -3, c = -5
Your answer is correct!! 2/3
Answer:
Step-by-step explanation:
y=-1/2(x+10)^2+14
2y=-(x+10)^2+28
(x+10)^2=28-2y
L.H.S. is positive.
so 28-2y≥0
28≥2y
or 2y≤28
or y≤ 14
Range is (-∞,14]
