A) 15/4 = 4/4+4/4+4/4+3/4= 3 3/4
B)9/2= 2/2+2/2+2/2+2/2+1/2= 4 1/2
c = 26/12 = 12/12 + 12/12 + 2/12 = 2 2/12
d) 20/6 = 6/6 + 6/6 + 6/6 + 2/6 = 3 2/6
Answer: c)[50,60]
Step-by-step explanation:
The Empirical rule says that , About 68% of the population lies with the one standard deviation from the mean (For normally distribution).
We are given that , The heights of students in a class are normally distributed with mean 55 inches and standard deviation 5 inches.
Then by Empirical rule, about 68% of the heights of students lies between one standard deviation from mean.
i.e. about 68% of the heights of students lies between 
i.e. about 68% of the heights of students lies between 
Here, 
i.e. The required interval that contains the middle 68% of the heights. = [50,60]
Hence, the correct answer is c) (50,60)
P(A) =0.54
P(B)= 0.68
P'(A)= 1-0.54 = 0.46
P'(B)= 1- 0.68 = 0.32
The probability of neither of both event will occur:
= P'(A)×P'(B)
=0.46 × 0.32
=0.1472
Let x be the width of the playground, then 3x is the length of the
<span>playground
х * 3х = 75
3x</span>² = 75
x² = 25
x = 5 m (width)
5*3=15 m (length)
Perimeter = 2(5+15) = 2*20 = 40 meters.
If you would like to solve the system of equations 5x + 4y = 12 and 3x - 3y = 18 using elimination, you can do this using the following steps:
<span>5x + 4y = 12 /*3
3x - 3y = 18 /*4
_____________
15x + 12y = 36
12x - 12y = 72
_____________
15x + 12y + 12x - 12y = 36 + 72
15x + 12x = 36 + 72
27x = 108
x = 108/27
x = 4
</span><span>3x - 3y = 18
</span>3 * 4 - 3y = 18
12 - 3y = 18
12 - 18 = 3y
3y = -6
y = -6/3
y = -2
(x, y) = (4, -2)
The correct result would be: x = 4 and y = -2.