Two students in different classes took the same math test. Both students received a
score of 87. In student A's class the mean was 78 and the standard deviation of 5. In
student B's class the mean was 76 with a standard deviation of 4. Which student
scored in the top 10% of their class?
Answer:
Both students scored in the top 10% of their classes.
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
In this question:
Top 10% = Above the 100 - 10 = 90th percentile.
The 90th percentile of scores is X when Z has a pvalue of 0.9, that is, Z = 1.28.
So, the student who had a z-score above 1.28 scored in the 90th percentile of their class.
In student A's class the mean was 78 and the standard deviation of 5. He scored 87.
We have that [tex]\mu = 78, \sigma = 5, X = 87[/tex]
Then
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{87 - 78}{5}[/tex]
[tex]Z = 1.8[/tex]
1.8 > 1.28, so student A scored in the top 10% of his/her class.
Student B's class the mean was 76 with a standard deviation of 4. Scored 87.
We have that [tex]\mu = 76, \sigma = 4, X = 87[/tex]
Then
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{87 - 76}{4}[/tex]
[tex]Z = 2.75[/tex]
2.75 > 1.28, so student B also scored in the top 10% of his/her class.
Both students scored in the top 10% of their classes.
Find the probability of exactly two
successes in five trials of a binomial
experiment in which the probability of
success is 50%.
Round to the nearest tenth of a
percent.
Answer:
Step-by-step explanation: 0.5
HELP ME LOOK AT THE PHOTO
Answer:
The answer to the question provided is 7.
Step-by-step explanation:
[tex]7x + 9 = 8x + 2 \\ \frac{ - 8x \: \: \: \: = - 8x}{ - 1x + 9 = 2 } \\ \frac{ \: \: \: \: \: \: \: \: - 9 = - 9}{ \frac{ - 1x}{ - 1} = \frac{ - 7}{ - 1} } \\ x = 7[/tex]
[I apologize if this isn't the answer]
What is the value of x in this figure?
Enter your answer in the box.
x=
Please help meeee!!
Answer:
x=48°
Step-by-step explanation:
We two lines cross over each other, making four angles, the angles opposite each other are equal. They're called vertically opposite angles.
find the surface area of the rectangular prism.
A 90 cm2
B 135 cm2
C 225 cm2
D 270 cm2
Answer:
D. 270 cm2
Step-by-step explanation:
2*(15*5 + 15*3 + 5*3) = 270 cm2
An cylindrical oatmeal container has a diameter of 5 inches and a volume of 239.425
in. What measurement is closest to the lateral surface area of the oatmeal
container?
230.81 in 2
o
191.54 in.2
15.24 in.2
478.85 in.2
Answer:478.85 in2
Step-by-step explanation:
Just divide LOL
Nathaniel is using the quadratic formula to solve 0 = x2 + 5x - 6. His steps are shown below/attached
What are solutions to the equations
Answer:
A
Step-by-step explanation:
Answer:
x= -6 ,1
Step-by-step explanation:
B is the answer
x= -6 ,1
Find the volume of a cylinder that has a radius of 1/2and a height of 1.
Answer:
0.79
Step-by-step explanation:
Which of the following would be the most appropriate unit to measure the volume of a bucket?
A. inch
B. cubic mile
C. cubic centimeter
D. cubic kilometer
Answer:
Volume uses cubic ___
A mile or kilometer is to big
So an cubic centimeter is about right
C
Equilateriall triangle. Find the length of side X in simple radical form with a rational denominator
Answer:
x = 4
Step-by-step explanation:
since the triangle is equilateral then the vertex angles are congruent, each 60°
using the sine ratio in the right triangle with x as its hypotenuse and the exact value
sin60° = [tex]\frac{\sqrt{3} }{2}[/tex] , then
sin60° = [tex]\frac{opposite}{hypotenuse}[/tex] = [tex]\frac{\sqrt{12} }{x}[/tex] = [tex]\frac{\sqrt{3} }{2}[/tex] ( cross- multiply )
x × [tex]\sqrt{3}[/tex] = 2[tex]\sqrt{12}[/tex] ( divide both sides by [tex]\sqrt{3}[/tex] )
x = [tex]\frac{2\sqrt{12} }{\sqrt{3} }[/tex] = 2 × [tex]\sqrt{\frac{12}{3} }[/tex] = 2 × [tex]\sqrt{4}[/tex] = 2 × 2 = 4
PLEASE HELP ME
Drag the tiles to the boxes to form correct pairs. Not all tiles will be used.
Match the expressions with their simplified forms.
(a) √2 · √8. The simplified surd expression is 4.
(b) √80. The simplified surd expression is 4√5.
(c) √5/√20. The simplified surd expression is 1/2.
(d) √20. The simplified surd expression is 2√5.
What is the simplification of the surd expression?The given surd expression is simplified as follows;
(a) √2 · √8
we can simplify it as;
√2 · √8 = √(2 x 8) = √16 = 4
(b) √80
we can simplify it as;
√80 = √ (16 x 5) = √16 x √5 = 4√5
(c) √5/√20
we can simplify it as;
√5/√20 x √20 / √20
= (√5 x √20 ) /(20)
= √100 / 20
= 10/20
= 1/2
(d) √20
we can simplify it as;
√20 = √4 x √5 = 2√5
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A football stadium holds 5000 people.
On a match day 5 of the stadium is full.
40% of the children are girls.
The ratio of adults to children is 2 : 3
How many of the children attending are boys?
Answer:
720 boysss
Step-by-step explanation:
Yep thts the answerrr...
are these correct???
Answer:
They are all correct.
Step-by-step explanation:
1.
1/2(b)(h)
1/2(4)(6)
1/2(24)
12
2. l x w
7 x 5
35
3. (b)(h)
(8)(4)
32
The distance between City A and City B is 500 miles. A length of 1.7 feet represents this distance on
a certain wall map. City C and City D are 2.72 feet apart on this map. What is the actual distance
between City C and City D?
The actual distance between City C and City Dis miles.
Answer:
799.99999 or 800 miles.
Step-by-step explanation:
You first need to find the conversion rate, so you divide 500 by the number representing it on the map, that being 1.7 feet. Once you've done this, you will get a conversion rate of 294. Now that you have the conversion rate, you multiply your second number, 2.72. This will give you your answer of 799.68 miles, which can be rounded up to 800 miles.
Can I have some help I don't really understand this question.
Answer:
40 square units
Step-by-step explanation:
This is a rhombus, so you multiply the two diagonals and divide by 2.
8x10÷2=40
If f(x)=x squared-2x and g(x) = 6x+4 for which is a value of x does (f+g)(x) =0
Answer:
For [tex]x = -2[/tex]
Step-by-step explanation:
Solving a quadratic equation:
Given a second order polynomial expressed by the following equation:
[tex]ax^{2} + bx + c, a\neq0[/tex].
This polynomial has roots [tex]x_{1}, x_{2}[/tex] such that [tex]ax^{2} + bx + c = a(x - x_{1})*(x - x_{2})[/tex], given by the following formulas:
[tex]x_{1} = \frac{-b + \sqrt{\Delta}}{2*a}[/tex]
[tex]x_{2} = \frac{-b - \sqrt{\Delta}}{2*a}[/tex]
[tex]\Delta = b^{2} - 4ac[/tex]
In this question:
[tex]f(x) = x^2 - 2x[/tex]
[tex]g(x) = 6x + 4[/tex]
[tex]f(x) + g(x) = (f+g)(x) = x^2 - 2x + 6x + 4 = x^2 + 4x + 4[/tex]
Which is a value of x does (f+g)(x) =0
[tex]x^2 + 4x + 4[/tex]
Quadratic equation with [tex]a = 1, b = 4, c = 4[/tex]
So
[tex]\Delta = 4^{2} - 4*1*4 = 0[/tex]
[tex]x_{1} = \frac{-4 + \sqrt{0}}{2} = -2[/tex]
[tex]x_{2} = \frac{-4 - \sqrt{0}}{2} = -2[/tex]
For [tex]x = -2[/tex]
Michael is buying a pair of jeans that regularly cost $40. They are on sale for 15% off. If the tax rate is 8.5%, what is the finale price of the jeans? Write ONE equation and solve.
Answer:
139284 238
Step-by-step explanation:
3. The third side of a triangle measures (3x-5) cm. If the length of the midline is 14 m,
what is x?
A 8
C. 10
B. 9
D. 11
Answer:
D. 11
Step-by-step explanation:
Midsegment theorem:
The length of the midsegment of a triangle is half the length of it's third side.
In this question:
Third side: 3x - 5
Midsegment: 14m
So
[tex]\frac{3x - 5}{2} = 14[/tex]
[tex]3x - 5 = 28[/tex]
[tex]3x = 33[/tex]
[tex]x = \frac{33}{3}[/tex]
[tex]x = 11[/tex]
The correct answer is given by option D.
Label the spinner below with the letters A though J. What is the probability of landing on a vowel on the spinner and rolling a number greater that 4 on the fair number cube?
Answer:
3 for vowles and two for number
Step-by-step explanation:
I also need help on this one just need points
The mean grade in Mathematics of Grade 11 students from school A is 83 with standard deviation of 4, while the mean grade in Mathematics of Grade 11 students from school B is 87 with standard deviation of 5. Using 49 samples from school A and 64 from school B, what is the probability that the mean grade of students from school B exceeds the mean grade of students from school A by at least 3 but less than 5?
Using the context surrounding the word trough in line 9 of "Concrete Mixers," explain what a trough looks like and what it does on a concrete mixer. .
sorry I can't delete it this not answer your question
Please help question in the picture
Answer:
64 m²
Step-by-step explanation:
Area of the trapezoid = ½(a + b)h
Where,
a = 6 m
b = 10 m
h = 8 m
Plug in the values
Area = ½(6 + 10)*8
Area = ½(16)*8
Area = 8*8
Area = 64 m²
What is the average rate of change of the function =2sin(1/2)on the interval [0, π]?
Answer:
4/x = [tex]\frac{\pi }{6}[/tex], 5 [tex]\frac{\pi }{6}[/tex]
Step-by-step explanation:
Sorry if I am wrong
The average rate of change of the function in the given interval [0, π] is [tex]\dfrac{2}{\pi }[/tex].
What is the average rate of change?The average Rate of Change of the function f(x) can be calculated as;
[tex]f(x) = \dfrac{f(b) - f(a)}{b-a}[/tex]
The given function is f(x) = 2sin(1/2)x on the interval [0, π]
Here a = 0
b = π
f(a) = 2sin(1/2)a
f(0) = 0
f(b) = 2sin(1/2)π = 2
Step 2: Find Average
[tex]f(x) = \dfrac{f(b) - f(a)}{b-a}\\\\f(x) = \dfrac{2- 0}{\pi }\\\\f(x) = \dfrac{2}{\pi }\\[/tex]
Therefore, the average rate of change of the function in the given interval [0, π] is [tex]\dfrac{2}{\pi }[/tex].
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here's this too!!!!!
Answer:
6. (a-4)(a+9)
7. (3p+4)(p-2)
8. Will explain below.
9. (5b+4)(5b-4)
Step-by-step explanation:
HELLOOO IM BACK
6. -4*9 = -36 (the variable), 9-4 = 5 (a) , so a^2 +5a - 36 is fulfilled.
7. 4*-2 = -8, 4-2 = 2, so 3p^2 - 2p - 8 is fulfilled.
9. 25b^2 = (5b)^2
16 = 4^2
Using the difference of squares formula, a^2-b^2= (a+b)(a-b)
In 2006, a sample of 200 in-store shoppers showed that 42 paid by debit card. In 2009, a sample of the same size showed that 80 paid by debit card. (a) Formulate appropriate hypotheses to test whether the percentage of debit card shoppers increased. (b) Carry out the test at alpha
The percentage of debit shoppers has increased.
21% (2006) < 40% (2009)
In 2006, the percentage of debit shoppers is 21%.
In 2009, the percentage of debit shoppers is 40%.
What is a percentage?The percentage is calculated by dividing the required value by the total value and multiplying by 100.
Example:
Required percentage value = a
total value = b
Percentage = a/b x 100
We have,
In 2006:
A sample of 200 in-store shoppers showed that 42 paid by debit card.
The percentage of debit shoppers in 2006.
= 42/200 x 100
= 42/2
= 21%
In 2009:
A sample of the same size showed that 80 were paid by debit card.
The percentage of debit shoppers in 2009.
= 80/200 x 100
= 40%
Thus,
The percentage of debit shoppers has increased.
21% (2006) < 40% (2009)
In 2006, the percentage of debit shoppers is 21%.
In 2009, the percentage of debit shoppers is 40%.
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HELP ASAP 6TH GRADE WORK LOOK AT PHOTO
The simplified exponential function is determined as x⁴.
What is the simplification of the exponential function?An exponential function is a mathematical function used to calculate the exponential growth or decay of a given set of data.
To simplify an exponential function, we will apply the rules of exponent as shown below;
The given exponential function;
= (∛ x² )⁶
The given expression is simplified as follows;
= [tex](x^2) ^{\frac{1}{3} \times 6}[/tex]
= ( x² )²
= x⁴
Thus, the simplified exponential function is determined by applying the rules of multiplication of powers.
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Can someone please give me this answer
Answer:
42°
Step-by-step explanation:
According to Exterior Angle Theorem,
an exterior angle of a ∆ is equal to the sum of the opposite interior angles.
So,
h+96°=138°
h=138°-96°
h=42°
Wendy bought a silver necklace online. It cost $23.15 plus 20% shipping and handling. What was the total cost?
The Wendy spent $27.78 on a silver necklace online.To calculate the total cost of the silver necklace, we need to add the cost of the necklace to the shipping and handling charges.
The cost of the necklace is given as $23.15.
Wendy bought a silver necklace online. It cost $23.15 plus 20% shipping and handling.
What was the total cost?When purchasing a silver necklace online, Wendy spent $23.15, but she had to pay for shipping and handling as well, which cost 20% of the total price of the item.
To find the total cost of the necklace, follow these steps:
1. Determine the cost of shipping and handling: $23.15 × 0.20 = $4.632
Add the cost of shipping and handling to the cost of the necklace:$23.15 + $4.63 = $27.78
The total cost of the necklace is $27.78.
It's important to consider the additional charges such as shipping and handling when calculating the total cost of an online purchase to have an accurate understanding of the amount spent.
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-2 4/5 divided by -7
Answer:
2/5 or 0.4
Step-by-step explanation:
convert -14/5 / (-7)
divide 14/5 / 7 ( two negatives equal a positive)
equals 2/5 or 0.4 in decimal
In the image below, line q is parallel to liner, and line s is a transversal.
D
9
B
What is the relationship between the measures of ZAand ZB?
The measures of Aand ZB are
becuase they are
Answer:
equal
alternate exterior angles
Step-by-step explanation:
The measure of given angles are equal to each other because they are alternate exterior angles,
Please help, will give brainliest.
Answer:
There is nothing.
Step-by-step explanation:
Answer:
A line that starts at with a constant positive slope
Step-by-step explanation:
Hope it makes sense!!