For a language test with normally distriuted scores, the mean was 70 and the standard deviation was 10. Approximately what perce
1 answer:
Answer: 84.13%
Step-by-step explanation:
Given : The scores in a a language test with normally distributed.
Mean :
Standard deviation:
Let x be the random variable that represents the scores of students.
Formula for z-score:
For x= 60 , we have
The probability f test takers scored a 60 or above :-
Hence, the percentage of test takers scored a 60 or above = 84.13%
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Answer:
30 hours.
Step-by-step explanation:
Richard can build 15 snowballs in 1 hour
But 2 snowballs melt every 15 minutes
In 1 hour, the number of snowballs that will have melted is:
× 2 = 8
The number of snowballs that will have remained = 15 - 8 = 7
So 7 snowballs will have remained in 1 hour
For 210 snowballs to have remained, it will take:
× 1 = 30 hours.
Answer: The correct options are (1) (5,10), (2) (3,-3), (3) x = -1, (4) , (5) 21s and (6) 0, -1, and 5.
Explanation:
Te standard form of the parabola is,
.....(1)
Where, (h,k) is the vertex of the parabola.
(1)
The given equation is,
Comparing this equation with equation (1),we get,
and
Therefore, the vertex of the graph is (5,10) and the fourth option is correct.
(2)
The given equation is,
To make perfect square add , i.e.,
. Since there is factor 3 outside the parentheses, so subtract three times of 9.
Comparing this equation with equation (1),we get,
and
Therefore, the vertex of the graph is (3,-3) and the fourth option is correct.
(3)
The given equation is
To make perfect square add , i.e.,
. Since there is factor 4 outside the parentheses, so subtract three times of 1.
Comparing this equation with equation (1),we get,
and
The vertex of the equation is (-1,3) so the axis is x=-1 and the correct option is 2.
(4)
The given equation is,
To make perfect square add , i.e.,
.
Therefore, the correct option is 4.
(5)
The given equation is,
It can be written as,
It is a downward parabola. so the maximum height of the function is on its vertex.
The x coordinate of the vertex is,
Therefore, after 21 seconds the projectile reach its maximum height and the correct option is first.
(6)
The given equation is,
Use factoring method to find the factors of the equation.
Equate each factor equal to 0.
Therefore, the zeros of the given equation is 0, -1, 5 and the correct option is 2.