Answer:
76 students scored above 80%.
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.
The mean examination mark of a random sample of 1390 students is 67% with a standard deviation of 8.1%.
This means that [tex]\mu = 67, \sigma = 8.1[/tex]
Proportion above 80:
1 subtracted by the p-value of Z when X = 80, so:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{80 - 67}{8.1}[/tex]
[tex]Z = 1.6[/tex]
[tex]Z = 1.6[/tex] has a p-value of 0.9452.
1 - 0.9452 = 0.0548.
Out of 1390 students:
0.0548*1390 = 76
76 students scored above 80%.
The graph shows the distribution of the number of text messages young adults send per day. The distribution is approximately Normal, with a mean of 128 messages and a standard deviation of 30 messages.
A graph titled daily text messaging has number of text on the x-axis, going from 8 to 248 in increments of 30. Data is distributed normally. The highest point of the curve is at 128.
What percentage of young adults send between 68 and 158 text messages per day?
34%
47.5%
81.5%
95%
This value is approximate.
====================================================
Explanation:
We have a normal distribution with these parameters
mu = 128 = population meansigma = 30 = population standard deviationThe goal is to find the area under the curve from x = 68 to x = 158, where x is the number of text messages sent per day. So effectively, we want to find P(68 < x < 158).
Let's convert the score x = 68 to its corresponding z score
z = (x-mu)/sigma
z = (68-128)/30
z = -60/30
z = -2
This tells us that the score x = 68 is exactly two standard deviations below the mean mu = 128.
Repeat for x = 158
z = (x-mu)/sigma
z = (158-128)/30
z = 30/30
z = 1
This value is exactly one standard deviation above the mean
-------------------------------------------
The problem of finding P(68 < x < 158) can be rephrased into P(-2 < z < 1)
We do this because we can then use the Empirical rule as shown in the diagram below.
We'll focus on the regions between z = -2 and z = 1. This consists of the blue 13.5% on the left, and the two pink 34% portions. So we will say 13.5% + 34% + 34% = 81.5%
Approximately 81.5% of the the population sends between 68 and 158 text messages per day. This value is approximate because the percentages listed in the Empirical rule below are approximate.
Answer:
C. 81.5%
Step-by-step explanation:
Help me please guys thanks
Answer:
A is correct
Step-by-step explanation:
 In one of the examples he is working on, he knows that the two coordinates (0,6) and
(8, 10) are on the function that he is deriving. Using the information from these two
coordinates, determine the slope and y-intercept of the function Mike is looking for, and
then write out the correct function.
9514 1404 393
Answer:
y = 1/2x + 6
Step-by-step explanation:
The slope m is given by the formula ...
m = (y2 -y1)/(x2 -x1)
m = (10 -6)/(8 -0) = 4/8 = 1/2
The y-intercept is given by the formula ...
b = y -mx
b = 6 -(1/2)(0) = 6
Then the slope-intercept equation is ...
y = mx +b
y = 1/2x +6
Given the directrix of y = 4 and focus of (0, 2), which is the equation of the parabola?
Answer:
The equation of the parabola is,
x²+4y-12=0
show that the line x-y+2=0 and the line joining the points (4,6) and (10,12) are parallel to each other
x-y+2=0
-y= -x-2
y=x+2
In order for the other line to be parallel, the slope has to be the same.
(12-6)/(10-4)= 6/6= 1
Both slopes are the same, meaning it is parallel.
A health club sold ten memberships in one week for total of $3000. If male memberships cost $300 and female memberships cost $300, then how many male memberships and how female memberships were sold?
Answer:
Step-by-step explanation:
The reason you haven't gotten an answer to this is because in its current formatting, there is no answer. Here's what I mean:
The first equation is going to be concerning the NUMBER of memberships sold, where m is male and f is female. The total number of memberships was 10:
m + f = 10
Now for the money equation. The total amount of money made from that number of memberships was 3000, where male memberships cost $300 and so do the female memberships, giving us an equation of
300m + 300f = 3000
Go back to the first equation and solve for either m or f. I solved for m in terms of f:
m = 10 - f and sub that into the second equation for m to get:
300(10 - f) + 300f = 3000 and
3000 - 300f + 300f = 3000. Here is where you find the problem. The -300f and the 300f cancel each other out, leaving you with the fact that
3000 = 3000 which it does, but it doesn't give us any viable answer.
I would have to say that since we can't do math on this, that the most credible answer you'll find is that the same number of male and female memberships were sold because 5 male memberships cost $1500 (5 memberships at $300 a piece is $1500) and 5 female memberships also cost $1500.
1500 + 1500 = 3000
Tay-Sachs disease is a genetic disorder that is usually fatal in young children. If both parents are carriers of the disease, the probability that their offspring will develop the disease is approximately 0.25. Suppose that a husband and wife are both carriers and that they have four children. If the outcomes of the four pregnancies are mutually independent, what are the probabilities of the following events?
a. All three children will develop Tay–Sachs disease.
b. Only one child will develop Tay–Sachs disease.
c. The third child will develop Tay–Sachs disease, given that the first two did not.
Lo siento mucho, necesito los puntos porque estoy en una prueba.
Please help ASAP please help me
9514 1404 393
Answer:
C) 12 cm
Step-by-step explanation:
In a 30°-60°-90° triangle, the ratios of side lengths are ...
1 : √3 : 2
This means the hypotenuse (AC) is 2/√3 times the length of the long side (AB).
(10 cm)(2/√3) = 20/√3 cm ≈ 11.55 cm
Rounded to the nearest cm, the length of AC is 12 cm.
Can you help with this
9514 1404 393
Answer:
D, C
Step-by-step explanation:
The only two rational expressions that have appropriate denominators are ...
1/(x² +6x) . . . contributes a factor of x to the denominator
(x+2)/(x² -36) . . . contributes a factor of (x -6) to the denominator
The proper order in the expression is ...
[tex]\displaystyle\dfrac{x+2}{x^2-36}-\dfrac{1}{x^2+6x}=\dfrac{x^2+x+6}{x(x-6)(x+6)}[/tex]
Answer:
(x+2/x^2-36) - (1/x^2+6x) = (x^2+x+6/x(x-6)(x+6))
Step-by-step explanation:
I hope that helps
how many wall are there in your room? what are the shape of the floor and ceiling in your room ? how can you find the area of each shape?prepare the answer. present the conclusion in the form of report. plz answer the question in right.how many wall are there in your room? what are the shape of the floor and ceiling in your room ? how can you find the area of each shape?prepare the answer. present the conclusion in the form of report. plz answer the question in right. plz answer the question steps by step.
Answer:
4 walls in my room. The shape of my room is square and my ceiling in square. By looking at it and measuring it. Thats how I found my answer.
I believe this is correct if it is can you mark brainliest? Hope I helped!!!! :)
Answer:
8 walls etc....
Step-by-step explanation:
Someone help me please
Answer:
y=4
Step-by-step explanation:
The triangle on the right is a 30-60-90 triangle
The ratio of sides in a 30-60-90 triangle is 1:√3:2
y:x:8
SO y will be 4 because 8/y=2/1
Do the two trapezoids in the figure appear to be similar? Why or why not?
options:
A)
They're not similar because only one pair of corresponding angles in the two trapezoids is congruent.
B)
They're similar because two pairs of corresponding angles in the two trapezoids are congruent.
C)
They're similar because one pair of corresponding angles in the two trapezoids is congruent.
D)
They're not similar because two pairs of corresponding angles in the two trapezoids are congruent.
Answer:
Option B,
They're similar because two pairs of corresponding angles in the two trapezoids are congruent
Answer:
They're not similar because only one pair of corresponding angles in the two trapezoids is congruent.
Step-by-step explanation:
What is the slope-intercept equation of the line below?
Answer:
y=-5/4x+3
Step-by-step explanation:
y=mx+c
m = (y1-y2)/(x1-x2) =(-2-3)/(4-0) =-5/4
sub the values y=3, x=0 to find c,
3 =-5/4(0) + c
c = 3
What is the greatest common factor of 10 and 13?
ANSWER IN LESS THEN 3 MINS AND I'LL GIVE BRAINLIEST
Answer:
the answer for this would be 1
gordan is twice as old as tony was when gordan was as old as tony is now. combined age of gordan and tony is 112 years. how old are gordan and tony now?
Answer:
Answer
Tony:48
Gordan :64
Step-by-step explanation:
[tex]\begin{array}{c|c|c}Age&Gordon&Tony\\------------------&-------&-------\\now&g&t\\when\ gordan\ was\ as\ old\ as\ tony\ is\ now&t(=g-g+t)&t-g+t=2t-g\\\end{array}\\\\\\\\\left\{\begin{array}{ccc}g&=&2*(2t-g)\\g+t&=&112\\\end {array}\right.\\\\\\\left\{\begin{array}{ccc}3g&=&4t\\g+t&=&112\\\end {array}\right.\\\\\\\left\{\begin{array}{ccc}g&=&\dfrac{4}{3}\\\dfrac{7}{3} t&=&112\\\end {array}\right.\\\\\\\left\{\begin{array}{ccc}t&=&48\\g&=&64\\\end {array}\right.\\[/tex]
Proof:
16 years ago, Gordan was 48 and Tony 32.
64=2*32
64+48=112
. Two mutually exclusive projects have projected cash flows as follows:
YEAR PROJECT A PROJECT B
0 Ksh. -2m Ksh. -2m
1 1m 0
2 1m 0
3 1m 0
4 1m 6m
Required:
a) Determine the internal rate of return for each project. [2 Marks]
b) Determine the net present value for each project at discount rates of 0, 5,10,20,30, and 35 percent. [2 Marks]
c) Plot a graph of the net present value of each project at the different discount rates. [2 Marks]
d) Which project would you choose? Why? [ 2 Marks]
e) What is each project’s MIRR if the cost of capital is 12 percent?
Answer:
yes
Step-by-step explanation:
Which of the following sets are equal to {x|x < 9 and x> 2}
{3,4,5,6,7,8}
{2,3,4,5,6,7,8,9}
{}
{2,3,4,5,6,7}
Answer:
{3, 4, 5, 6, 7, 8}Step-by-step explanation:
{x|x < 9 and x > 2}= {3, 4, 5, 6, 7, 8}[tex]\tt{ \green{P} \orange{s} \red{y} \blue{x} \pink{c} \purple{h} \green{i} e}[/tex]
A rectangle has an area of 616 m² and a width of 22m. What is its length?
Answer:
l=28m
w Width
22
m
A Area
616
m²
Using the formula
A=wl
Solving forl
l=A
w=616
22=28m
hope this will help you
make me brainliest
Answer:
Solve for length
l=28m
W= Width
22
m
A= Area
616
m²
Using the formula
A=wl
Solving formula
l=A
W=616
22=28m
In the equation 11 - 4(x +4) = 6x, the first step is to simplify 11 - 4.
True
False
Answer:
False
Step-by-step explanation:
You first need to distribute the -4 to (x+4).
Find the length of the segment indicated. circles 4
I need more information, comment on my "answer".
Integers are sometimes whole numbers
true or false
Answer:
True
Step-by-step explanation:
Integers are always whole numbers
negative, 0, positive:: whole numbers
HELP ME PLSSS SUMMER SCHOOL A HARD
Answer:
y=2x+8
Step-by-step explanation:
Hope this helps
please help with this on the picture
Answer:
There is not enough information to solve this problem :(
Tenisha solved the equation below by graphing a system of equations.
log35x = log (2x+8)
Which point approximates the solution for Tenisha's system of equations?
0 (0.9, 0.8)
O (1.0, 1.4)
O (2.3, 1.1)
O (2.7, 13.3)
Answer:
Option B.)
Step-by-step explanation:
Just took the test and got 100% :]
The system of logarithmic equation is graphed and the point of intersection of the equation is log₃ ( 5x ) = log₅ ( 2x + 8 ) is A ( 1.0 , 1.4 )
What is Equation of Graph of Polynomials?Graphs behave differently at various x-intercepts. Sometimes the graph will cross over the x-axis at an intercept. Other times the graph will touch the x-axis and bounce off.
Identify the even and odd multiplicities of the polynomial functions' zeros.
Using end behavior, turning points, intercepts, and the Intermediate Value Theorem, plot the graph of a polynomial function.
The graphs cross or are tangent to the x-axis at these x-values for zeros with even multiplicities. The graphs cross or intersect the x-axis at these x-values for zeros with odd multiplicities
Given data ,
Let the solution to the logarithmic equation be represented as A
Now , the value of A is
log₃ ( 5x ) = log₅ ( 2x + 8 )
On simplifying , we get
log₃ ( 5x ) = log₁₀ ( 5x ) / log₁₀ ( 3 )
log₅ ( 2x + 8 ) = log₁₀ ( 2x + 8 ) / log₁₀ ( 5 )
Substituting the logarithmic quantities , we get
log₁₀ ( 5x ) / log₁₀ ( 3 ) = log₁₀ ( 2x + 8 ) / log₁₀ ( 5 )
On cross multiplying , we get
log₁₀ ( 5x ) / log₁₀ ( 2x + 8 ) = log₁₀ ( 3 ) / log₁₀ ( 5 )
( 5x ) / ( 2x + 8 ) = 3/5
On cross multiplying , we get
25x = 6x + 24
Subtracting 6x on both sides , we get
19x = 24
Divide by 19 on both sides , we get
x = 1.26
Therefore , the approximate values of the function on graphing is A ( 1.0 , 1.4 )
Hence , the solution of function from graphing is A ( 1.0 , 1.4 )
To learn more about equation of graph of polynomials click :
https://brainly.com/question/16957172
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A service station has both self-service and full-service islands. On each island, there is a single regular unleaded pump with two hoses. Let X denote the number of hoses being used on the self-service island at a particular time, and let Y denote the number of hoses on the full-service island in use at that time. The joint pmf of X and Y appears in the accompanying tabulation. y p(x, y) 0 1 2 x 0 0.10 0.03 0.02 1 0.06 0.20 0.07 2 0.05 0.14 0.33 (a) What is P(X
Answer:
[tex]P(x = 1) = 0.33[/tex]
[tex]P(y = 2) = 0.42[/tex]
Step-by-step explanation:
Given
y
x [tex]\begin{array}{cccc}P(x,y) & {0} & {1} & {2} & {0} & {0.10} & {0.03} & {0.02} & {1} & {0.06} & {0.20} & {0.07} & {2} & {0.05} & {0.14} & {0.33}\ \end{array}[/tex]
Solving (a)
[tex]P(x = 1)[/tex]
To do this, we simply add all data where x = 1
So, we have:
[tex]P(x = 1) = P(x=1|y=0) + P(x=1|y=1) + P(x=1|y=2)[/tex]
[tex]P(x = 1) = 0.06 + 0.20 + 0.07[/tex]
[tex]P(x = 1) = 0.33[/tex]
Solving (b)
[tex]P(y = 2)[/tex]
To do this, we simply add all data where y = 2
So, we have:
[tex]P(y = 2) = P(x=0|y=2) + P(x=1|y=2) + P(x=2|y=2)[/tex]
[tex]P(y = 2) = 0.02 + 0.07 + 0.33[/tex]
[tex]P(y = 2) = 0.42[/tex]
PLSSS HELP IM STRUGGLING SO HARD !!! ———————
Answer:
C)
Step-by-step explanation:
Just see the length of the R line, A and B are almost the same large when you add them.
please give me correct answer
Answer:
answer of question number 1 is 2400, 2880, 3600 respectively.
answer of question number 2 is 1384 and 1680.
Step-by-step explanation:
100×24=2400
120×24=2880
150×24=3600
692×2=1384
420×4=1680
Find mPMA + mCMT. Please help..
PMA = 37
CMT = 101 - 54 =47
Total = 37 + 47 = 84
Answer: A. 84
Find the length of BC
Since this is a right triangle, we can use one of the three main trigonometric functions: sine, cosine or tangent.
Remember: SOH-CAH-TOA
Looking from the given angle, we want to find the opposite side and we know the hypotenuse. Therefore, we should use sine.
sin(51) = BC / 58
BC = 58 x sin(51)
BC = 45.1 units
Hope this helps!
Step-by-step explanation:
Hey there!
From the above given figure;
Angle CAB = 51°
AB = 58
Taking Angle CAB as reference angle we get;
Perpendicular (p) = BC= ?
Hypotenuse (h) = 58
Now;
Taking the ratio of sin we get;
[tex] \sin( \alpha ) = \frac{p}{h} [/tex]
[tex] \sin(51) = \frac{bc}{58} [/tex]
Simplify it;
0.7771459*58 = BC
Therefore, BC = 45.0744.
Hope it helps!
Put the following equation of a line into slope-intercept form, simplifying all
fractions.
18x + 3y = -18
Answer:
y= -6x-6, I think, hope it helped
Step-by-step explanation:
