You'll need to calculate the applicable z-score:
(given value of x) - (mean value)
z = -----------------------------------------------
standard deviation
370-400 -30
Here, z = --------------- = ---------- = -0.3
100 100
Use either a table of z scores or your calculator to determine the area under the standard normal curve to the left of z = -0.3.
According to my TI-83 Plus calculator, this area is 0.382.
The probability of selecting at random a score less than or equal to 370 is 0.382.
Let the number be x:
3*x-2=13
∴3x=13+2
∴3x=15 (divide both sides by 3)
∴x=5 the answer is C
5 = 60
6 = 150
7 = 30
if you have any more questions let me know
Answer:
Least to most -
Step-by-step explanation:
Peanuts
Popcorns
Soda
Hotdogs
If the discriminant is negative no real solution exists.
If the discriminant is equal to 0 only one real solution exists.
If the discriminant is positive 2 real solutions exist.
The discriminant:
D = b² - 4 a c
1 ) - 7 x² + 6 x + 3 = 0
D = 6² - 4 · ( - 7 ) · 3 = 36 + 84 = 120 > 0
Answer: b) two solutions
2 ) - 8 x² - 8 x - 2 = 0
D = ( - 8 )² - 4 · ( - 8 ) · ( - 2 ) = 64 - 64 = 0
Answer: a ) one solution
