Answer:
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the scores of a population, and for this case we know the distribution for X is given by:
Where 
and 
We are interested on this probability
And the best way to solve this problem is using the normal standard distribution and the z score given by:
If we apply this formula to our probability we got this:
And we can find this probability using the normal standard table or excel and we got:
Answer:
(x+a) (x+b)=x(x+b)+a(x+b)=x²+bx+ax+ab=x²+x(a+b)+ab
Answer:
x = 5/2
Step-by-step explanation:
Solve for x:
(5 x)/2 = 25/4
Hint: | Multiply both sides by a constant to simplify the equation.
Multiply both sides of (5 x)/2 = 25/4 by 2/5:
(2×5 x)/(5×2) = 2/5×25/4
Hint: | Express 2/5×5/2 as a single fraction.
2/5×5/2 = (2×5)/(5×2):
(2×5)/(5×2) x = 2/5×25/4
Hint: | Express 2/5×25/4 as a single fraction.
2/5×25/4 = (2×25)/(5×4):
(2×5 x)/(5×2) = (2×25)/(5×4)
Hint: | Cancel common terms in the numerator and denominator of (2×5 x)/(5×2).
(2×5 x)/(5×2) = (5×2)/(5×2)×x = x:
x = (2×25)/(5×4)
Hint: | In (2×25)/(5×4), divide 25 in the numerator by 5 in the denominator.
25/5 = (5×5)/5 = 5:
x = (2×5)/4
Hint: | In (2×5)/4, divide 4 in the denominator by 2 in the numerator.
2/4 = 2/(2×2) = 1/2:
Answer: x = 5/2
<h3>
Answer:</h3>
5/2
<h3>
Step-by-step explanation:</h3>
The ratio of perimeters is the same as the ratio of corresponding sides:
... (140 cm)/(56 cm) = 5/2
Answer:
23) option c
JL ≈ 9.3
25) option c
y ≈ 9.6
Step-by-step explanation:
<h3>25)</h3>
Given in the question that,
cos(21°) = 9 / y
y = 9/cos(21°)
y = 9.64
y ≈ 9.6(nearest tenth)
<h3>23)</h3>
Given in the question that the hypotenuse of right angle triangle = 12
To find,
height of the right angle triangle
angle k = 39°
so by using trigonometry identity
cos(39) = opp/hypo
cos(39) = JL / KL
JL = cos(39)(12)
JL = 9.32
JL ≈ 9.3
<h3 />
