50% since you have a half chance of getting 1 to 4 and other half is 4-8
The answer to your question is b
Let X be the national sat score. X follows normal distribution with mean μ =1028, standard deviation σ = 92
The 90th percentile score is nothing but the x value for which area below x is 90%.
To find 90th percentile we will find find z score such that probability below z is 0.9
P(Z <z) = 0.9
Using excel function to find z score corresponding to probability 0.9 is
z = NORM.S.INV(0.9) = 1.28
z =1.28
Now convert z score into x value using the formula
x = z *σ + μ
x = 1.28 * 92 + 1028
x = 1145.76
The 90th percentile score value is 1145.76
The probability that randomly selected score exceeds 1200 is
P(X > 1200)
Z score corresponding to x=1200 is
z = 
z = 
z = 1.8695 ~ 1.87
P(Z > 1.87 ) = 1 - P(Z < 1.87)
Using z-score table to find probability z < 1.87
P(Z < 1.87) = 0.9693
P(Z > 1.87) = 1 - 0.9693
P(Z > 1.87) = 0.0307
The probability that a randomly selected score exceeds 1200 is 0.0307
Answer:
a+305/36
Step-by-step explanation:
Convert
3
1
4
3
1
4
to an improper fraction.
a
+
13
4
+
5
2
9
a
+
13
4
+
5
2
9
Convert
5
2
9
5
2
9
to an improper fraction.
a
+
13
4
+
47
9
a
+
13
4
+
47
9
To write
13
4
13
4
as a fraction with a common denominator, multiply by
9
9
9
9
.
a
+
13
4
⋅
9
9
+
47
9
a
+
13
4
⋅
9
9
+
47
9
To write
47
9
47
9
as a fraction with a common denominator, multiply by
4
4
4
4
.
a
+
13
4
⋅
9
9
+
47
9
⋅
4
4
a
+
13
4
⋅
9
9
+
47
9
⋅
4
4
Write each expression with a common denominator of
36
36
, by multiplying each by an appropriate factor of
1
1
.
a
+
13
⋅
9
36
+
47
⋅
4
36
a
+
13
⋅
9
36
+
47
⋅
4
36
Combine the numerators over the common denominator.
a
+
13
⋅
9
+
47
⋅
4
36
a
+
13
⋅
9
+
47
⋅
4
36
Simplify the numerator.
a
+
305
36
a
+
305
36
Answer:
y = 20
Step-by-step explanation:
y = kx
24 = 6k
24/6 = 6k/6
k = 4
y = kx
y = 4(5)
y = 20