We are given:
p = probability = 0.12<span>
n = total students = 39 </span>
x = left handers = 5<span>
u = mean = p* n = 4.68
σ = standard dev = √ ( n*p*(1-p)) = √ ( 39 * 0.12 * 0.88 ) =
2.03</span>
Calculating for the z score:
z = (x – u) / σ<span>
z = (5 – 4.68) / 2.03</span>
<span>z
= 0.1576 = 0.16
</span>
Using the standard tables for z, the p value is:
p value = 0.5636 = 56.36%
Hence there is a 56.36% chance.
<span> </span>
Answer:
a) Percentage of students scored below 300 is 1.79%.
b) Score puts someone in the 90th percentile is 638.
Step-by-step explanation:
Given : Suppose a student's score on a standardize test to be a continuous random variable whose distribution follows the Normal curve.
(a) If the average test score is 510 with a standard deviation of 100 points.
To find : What percentage of students scored below 300 ?
Solution :
Mean 
,
Standard deviation 
Sample mean 
Percentage of students scored below 300 is given by,
Percentage of students scored below 300 is 1.79%.
(b) What score puts someone in the 90th percentile?
90th percentile is such that,
Now, 
Score puts someone in the 90th percentile is 638.
Answer:
x = -2/5
y = 12/5
Step-by-step explanation:
Substitution method;
-2x + 3y = 8 -----------(i)
x + y =2 -----------(ii)
x = 2 - y
substitute the value of x in equ (i)
(-2)* (2-y) + 3y = 8
-4 + 2y + 3y = 8
5y = 8 + 4
y = 12/5
substitute the value of y in equ (ii)
x + 12/5 = 2
x = 2 - 12/5
= 2*5/1*5 - 12/5
= 10 -12/5 = -2/5
Ans: x = -2/5
y = 12/5
elimination method:
-2x + 3y = 8 -----------(i)
x + y =2 -----------(ii)
(i) ====> -2x + 3y = 8
multiply equ (ii) by 2 ====> <u> 2x + 2y = 4</u>
add (i) and (ii) 5y = 12
y = 12/5
Substitute in equ (ii)
x + 12/5 = 2
x = 2 - 12/5
= 2*5/1*5 - 12/5
= 10 -12/5 = -2/5
Ans: x = -2/5
y = 12/5
Answer:
4
x
−
1
3
y
=
−
2
To convert this equation to slope-intercept form, solve for
y
.
Subtract
4
x
from both sides.
−
1
3
y
=
−
2
−
4
x
Simplify
−
1
3
y
to
−
y
3
−
y
3
=
−
2
−
4
x
Multiply both sides times
3
.
−
y
=
−
2
(
3
)
−
4
x
(
3
)
Simplify.
−
y
=
−
6
−
12
x
Rearrange the right side.
−
y
=
−
12
x
−
6
Multiply both sides times
−
1
.
y
=
12
x
+
6
m
=
12
and
b
=
6
.
Step-by-step explanation:
Answer:
25
Step-by-step explanation:
Let x be the number of students in the class
15 is 60% of x
60% of x can be written as 0.6x
15 = 0.6x
Divide by 0.6 on both sides
25 = x
There are 25 students in the class
Hope this helps :)
