There are 2229 students in a school district. Among a sample of 452 students from this school district, 163 have mathematics scores below grade level. Based on this sample, estimate the number of students in this school district with mathematics scores below grade level.
a. 804
b. 844
c. 884
d. 0.36
Answer:
A. 804Step-by-step explanation:
Given the total number of students in the school to be 2229 students. If among a sample of 452 students from this school district, 163 have mathematics scores below grade level, then we can determine the number of students in this school district with mathematics scores below grade level based on the sample scores using ratio.
Let the number of students in this school district with mathematics scores below grade level be x. The ratio of the students with math score below grade level to total population will be x:2229
Also, the ratio of the sample students with math score below grade level to sample population will be 163:452
On equating both ratios, we will have;
x:2229 = 163:452
[tex]\dfrac{x}{2229} = \dfrac{163}{452}\\ \\cross\ multiplying;\\\\\\452*x = 2229*163\\\\x = \dfrac{2229*163}{452}\\ \\x = \frac{363,327}{452}\\ \\x = 803.8\\\\x \approx 804[/tex]
Hence the estimate of the number of students in this school district with mathematics scores below grade level based on the sample is 804
Determine the number of degrees of freedom for the two-sample t test or CI in each of the following situations. (Round your answers down to the nearest whole number.)
(a) m = 12, n = 15, s1 = 4.0, s2 = 6.0
(b) m = 12, n = 21, s1 = 4.0, s2 = 6.0
(c) m = 12, n = 21, s1 = 3.0, s2 = 6.0
(d) m = 10, n = 24, s1 = 4.0, s2 = 6.0
Answer:
a
[tex]df = 24.32[/tex]
b
[tex]df = 30.10[/tex]
c
[tex]df = 30.7[/tex]
d
[tex]df = 25.5[/tex]
Step-by-step explanation:
Generally degree of freedom is mathematically represented as
[tex]df = \frac{ [\frac{ s^2_i }{m} + \frac{ s^2_j }{n} ]^2 }{ \frac{ [ \frac{s^2_i}{m} ]^2 }{m-1 } +\frac{ [ \frac{s^2_j}{n} ]^2 }{n-1 } }[/tex]
Considering a
a) m = 12, n = 15, s1 = 4.0, s2 = 6.0
[tex]df = \frac{ [\frac{ 4^2 }{12} + \frac{ 6^2 }{15} ]^2 }{ \frac{ [ \frac{4^2}{12} ]^2 }{12-1 } +\frac{ [ \frac{6^2}{15} ]^2 }{15-1 } }[/tex]
[tex]df = 24.32[/tex]
Considering b
(b) m = 12, n = 21, s1 = 4.0, s2 = 6.0
[tex]df = \frac{ [\frac{ 4^2 }{12} + \frac{ 6^2 }{21} ]^2 }{ \frac{ [ \frac{4^4}{12} ]^2 }{12-1 } +\frac{ [ \frac{6^2}{21} ]^2 }{21-1 } }[/tex]
[tex]df = 30.10[/tex]
Considering c
(c) m = 12, n = 21, s1 = 3.0, s2 = 6.0
[tex]df = \frac{ [\frac{ 3^2 }{12} + \frac{ 6^2 }{21} ]^2 }{ \frac{ [ \frac{3^4}{12} ]^2 }{12-1 } +\frac{ [ \frac{6^2}{21} ]^2 }{21-1 } }[/tex]
[tex]df = 30.7[/tex]
Considering c
(d) m = 10, n = 24, s1 = 4.0, s2 = 6.0
[tex]df = \frac{ [\frac{ 4^2 }{10} + \frac{ 6^2 }{24} ]^2 }{ \frac{ [ \frac{4^2}{10} ]^2 }{10-1 } +\frac{ [ \frac{6^2}{24} ]^2 }{24-1 } }[/tex]
[tex]df = 25.5[/tex]
what should be added to 66.778 get 78.2
Answer:
11.422
Step-by-step explanation:
[tex]78.2 - 66.778 \\ = 11.422[/tex]
Please Help quick!!! What is the value of a missing angle?
Answer:
69
Step-by-step explanation:
90-21=69
Answer:
69 degrees
Step-by-step explanation:
The full angle = 90 degrees.
One part of the full angle = 21 degrees
The other part of the full angle = x
Other angle = 90 - 21
=> the other angle = 69 degrees
7.619 by 10^-3
7.254 by 10^2
Answer:
0.007619
0.07254
Step-by-step explanation:
1)7.619*10^-3
0.007619
2)7.254*10^2
0.07254
Explanation:
7.619*10^-3
The number here is 7.619 and the number written in scientific notation has minus 3 as its exponent.
.007.619
So the distance between the first decimal point and the second decimal is only three numbers.
Since it is exponent is minus three.
Another way to get the answer.
[tex]7.619 \times 10 {}^{ - 3} = \frac{7619}{1000} \times \frac{1}{1000} = \frac{7619}{1000000} = 0.007619 [/tex]
This applies to the second one too.
Hope this helps ;) ❤❤❤
In one city, 35% of all aluminum cans distributed will be recycled each year. A juice company distributes 110,000 cans. The number still in use after time t, in years, is given by
Answer: [tex]n(t) = 110000(0.35)^t[/tex]
Step-by-step explanation:
Given: Rate of of all aluminum cans distributed will be recycled each year. = 35%
= 0.35
Total cans distributed = 110,000
Now , the number of cans recycled in 1 year = 110,000 ×0.35
The number of cans recycled in 2 years = 110,000 ×0.35 ×0.35 = 110,000 ×(0.35)²
..so on
The number of cans recycled in t years = [tex]110000(0.35)^t[/tex]
Let n(t) be the number still in use after time t, in years:
Then, [tex]n(t) = 110000(0.35)^t[/tex]
pls helpppp find the total area of the prism
Answer:
Total area = [tex](54+\frac{9\sqrt{3} }{2})[/tex] square inch
Step-by-step explanation:
Total area of the prism = Area of the rectangular sides (lateral sides) + area of the triangular bases
Area of the rectangular sides = 3 × (length × width)
= 3 × (3 × 6)
= 54 square inch
Area of the triangular bases = 2 × (Area of an equilateral triangle)
= 2 × [tex]\frac{\sqrt{3}}{4}(\text{Side})^2[/tex]
= [tex]\frac{\sqrt{3}}{2}(\text{Side})^2[/tex]
= [tex]\frac{\sqrt{3}}{2}(3)^2[/tex]
= [tex]9(\frac{\sqrt{3} }{2})[/tex]
= [tex]\frac{9\sqrt{3}}{2}[/tex] square inch
Total surface area = (54 + [tex]\frac{9\sqrt{3}}{2}[/tex]) square inch
Help! Solve equation: xe^2x=0
Answer: x=0
Step-by-step explanation:
For this problem, there are no calculations needed. You just have to know your algebraic properties. Since we are looking for x, we know that x must be 0. The answer is 0. Figuring out e²ˣ can be tricky, but since there is an x multiplying it in front, we know that x must be 0 to make the equation equal to 0.
In a lottery game, a player picks 6 numbers from 1 to 50. If 5 of the 6 numbers match those drawn, the player wins second prize. What is the probability of winning this prize
Answer:
1/254,251,200 Or 0.000000003933118
Step-by-step explanation:
1/50x1/49x1/48x1/47x1/46=1/254,251,200
If the legs of an isosceles right triangle have a length of 15 StartRoot 2 EndRoot ft, what is the length of the hypotenuse?
Answer:
30 ft
Step-by-step explanation:
a² + b² = c²
(15sqrt(2))² + (15sqrt(2))² = c²
225 * 2 + 225 * 2 = c²
c² = 900
c = sqrt(900)
c = 30
Answer: 30 ft
Answer:
30 ft
Step-by-step explanation:
a² + b² = c²
(15sqrt(2))² + (15sqrt(2))² = c²
225 * 2 + 225 * 2 = c²
c² = 900
c = sqrt(900)
c = 30
Answer: 30 ft
A slot machine has 3 dials. Each dial has 30 positions, one of which is "Jackpot". To win the jackpot, all three dials must be in the "Jackpot" position. Assuming each play spins the dials and stops each independently and randomly, what are the odds of one play winning the jackpot?
since there are 3 slots and each slot has 30 positions:
dial 1 can have a max of 30 possible outcomes, and so can dial 2 and 3
hence all the dial have 30 possible outcomes
total combinations = total outcomes of slot 1 X total outcomes of slot 2 X total outcomes of slot 3/ 3!
total combinations = 30 * 30 * 30 / 3 X 2 X 1
total combinations = 9000/3 X 2
total combinations = 1500
hence, there is a total of 1500 different combinations of the 3 slots
the combination required is 1 from the 1500
hence the odds are 1/1500
Answer:
1/27000
Step-by-step explanation:
30*30*30 =27000
each dial has to be in correct position so 1/27000 is correct
A school newspaper reporter decides to randomly survey 15 students to see if they will attend Tet festivities this year. Based on past years, she knows that 24% of students attend Tet festivities. We are interested in the number of students who will attend the festivities.
Find the probability that at most 4 students will attend. (Round your answer to four decimal places.)
Answer:
0.70319018
Step-by-step explanation:
Given the following:
Number of students surveyed (n) = 15
Probability of attending tet festival (p) = 24% =0.24
Therefore,
Probability of not attending (1 - p) = (1 - 0.24) = 0.76.
The probability that at most 4 students will attend can be obtained using the binomial probability relation:
p(x) = nCx * p^x * (1 - p)^(n-x)
At most 4 students means:
p(x=0) + p(x=1) + p(x=2) + p(x=3) + p(x=4)
p(x=0) = 15C0 * 0.24^0 * 0.76^(15 - 0)
p(x=0) = 1 * 1 * 0.0004701 = 0.00047018
p(x=1) = 15C1 * 0.24^1 * 0.76^(14)
p(x=1) = 15 * 0.24 * 0.021448 = 0.07721
p(x=2) = 15C2 * 0.24^2 * 0.76^(13) =
p(x=2) = 105 * 0.0576 * 0.02822 = 0.17068
p(x=3) = 15C3 * 0.24^3 * 0.76^(12)
p(x=3) = 455 * 0.013824 * 0.037133 = 0.23356
p(x=4) = 15C4 * 0.24^4 * 0.76^(11) =
p(x=4) = 1365 * 0.0033177 * 0.048859 = 0.22127
0.00047018 + 0.07721 + 0.17068 + 0.23356 + 0.22127 = 0.70319018
The residents of a city voted on whether to raise property taxes. The ratio of yes votes to no votes was 6 to 5 . If there were 4545 no votes, what was the total number of votes?
Answer:
The total number of votes= 9999
Step-by-step explanation:
The ratio of vote specifically the ratio of yes to no vote in a city vote is 6 to 5.
There is a total of 4545 no votes.
Yes/no = 6/5
Yes= no(6/5)
Yes= 4545(6/5)
Yes= 5454
The total number of yes votes are 5454.
The total number of votes= yes votes+ no votes
The total number of votes= 5454+4545
The total number of votes= 9999
Solve the equation for the given variable x/4=6/8
Answer:
x = 3
Step-by-step explanation:
This process is called cross multiplication.
Multiply 6 · 4 = 24
Divide 24 ÷ 8 = 3
x = 3
Answer:
x = 3
Step-by-step explanation:
x/4 = 6/8
Using cross products
x*8 = 4*6
8x = 24
Divide by 8
8x/8 = 24/8
x = 3
An empty swimming pool is to be filled to the top. The pool is shaped like a rectangular prism with length 10m, width 8m , and depth 4m. Suppose water is pumped into the pool at a rate of 16m cubed per hour. How many hours does it take to fill the empty pool?
Answer:
20 hours
Step-by-step explanation:
10*8*4=320 (volume of the pool)
320/16=20 hours
Answer:
20 hours
Step-by-step explanation:
10x8x4 = 320
320 / 16 = 20
it takes 20 hours to fill the empty pool
What is the radius of the circle whose center is the
origin and that passes through the point (5,12)?
Answer:
13 units
Step-by-step explanation:
Use the equation of a circle, (x - h)² + ( y - k )² = r², where (h, k) is the center and r is the radius.
Plug in the values and solve for r:
(5 - 0)² + (12 - 0)² = r²
25 + 144 = r²
169 = r²
13 = r
Robert has $20,000, part or all of which he wants to invest into a combination of government bonds and municipal bonds. He wants to invest no more than $5,000 into municipal bonds, and at least twice as much into government bonds than into municipal bonds.
Answer:
x + y ≤ 20,000y ≤ 5,000x ≥ 2yStep-by-step explanation:
Given:
Total amount = $20,000
Assume
Government bonds = x
Municipal bonds = y
Computation:
1. Invest total money
x + y ≤ 20,000
2. invest no more than $5,000 into municipal bonds
y ≤ 5,000
3. at least twice as much into government bonds.
x ≥ 2y
What is the simplified form of x minus 5 over x squared minus 3x minus 10⋅ x plus 2 over x squared plus x minus 12 ? (6 points) Select one: a. 1 over the quantity x minus 3 times the quantity x plus 4 b. 1 over the quantity x minus 3 times the quantity x plus 2 c. 1 over the quantity x plus 4 times the quantity x minus 5 d. 1 over the quantity x plus 2 times the quantity x minus 5
Answer:
[tex]\ \text{a. }\quad\dfrac{1}{(x-3)(x+4)}[/tex]
Step-by-step explanation:
Maybe you want the product ...
[tex]\dfrac{x-5}{x^2-3x-10}\cdot\dfrac{x+2}{x^2+x-12}=\dfrac{x-5}{(x-5)(x+2)}\cdot\dfrac{x+2}{(x-3)(x+4)}\\\\=\boxed{\dfrac{1}{(x-3)(x+4)}}[/tex]
__
Numerator factors of (x-5) and (x+2) cancel those in the denominator.
Write 41/12 as a decimal. If necessary, use a bar to indicate which digit or group of digits repeats. Write as a decimal.
Answer:
3.416, bar above 6
Step-by-step explanation:
41/12 = 3.4166666666666
41/12 = 3 & 5/12
Answer:
66
Step-by-step explanation:
41/12 = 3.4166
Find the area of the irregularly-shaped hexagon below
let each box length be 1
for white triangle
area = ½bh
=½(4)(2)
=4
for orange triangle
area=½(2)(3)
=3
for blue marked boxes
each of the box
area=l²
=(1)²
=1
there are 16 boxes
so the total area will be 16
total area of the hexagon = 4+3+16
=23 square units
[tex]A_1=\dfrac{1}{2}(3+5)\cdot 3=12\\A_2=1\cdot5=5\\A_3=\dfrac{1}{2}(5+1)\cdot 2=6[/tex]
So the area of the whole shape is [tex]12+5+6=23[/tex]
plz help i'm having a really hard time with this
Answer:
Domain all reals
Range all reals
Step-by-step explanation:
The domain is the values that x can take, or the values of the input
x can be any real number
The range is the values that y can take, or the values of the output
y can be any real number
Answer:
C)
Step-by-step explanation:
it's fully continous, linear function thus all values are possible for both, x and y
I suck at math, online school is really hard I need to find a tutor, can this be explained?
Answer:
its [c] if Bradley serves 4 tables he will earn an average of $25
Step-by-step explanation:
PLEASE HELP!!!!!! TIMED QUESTION!!!! FIRST CORRECT ANSWER WILL GET BRAINLIEST....PLEASE ANSWER NOW!!!!
The bar graph shows the number of students who earned each letter grade on an
exam, which statement about the graph is true?
1)
1/5 of the students earned a C
2)
3% more students earned an A then B
3)
20% of the students earned a D
4)
1/4 of the class earned a B
Answer:
3) 20% of the students earned a D
Step-by-step explanation:
9 students got a D.
5 students got a C.
14 students got a B.
17 students got an A.
Total number of students:
9 + 5 + 14 + 17 = 45
1) 1/5 of the students earned a C
1/5 of 45 = 9
5 students got a C
False
2) 3% more students earned an A then B
3 more students got an A than a B, but not 3%.
False
3) 20% of the students earned a D
20% of 45 = 9
9 students got a D.
True
4) 1/4 of the class earned a B
1/4 of 45 = 11.25
There were 14 B's.
False
Answer: 3) 20% of the students earned a D
6. Classify the traianle as scalene, isosceles or equilateral. Explain. Leave answers in square root form.
TAL
Answer:
isosceles
Step-by-step explanation:
The point B is located on the perpendicular bisector of AC. No calculation is necessary. AC has a slope of 1, so it is easy to count grid squares to see where the perpendicular bisector goes.
When the altitude of the triangle bisects the side opposite the vertex, it is an isosceles triangle.
_____
Apparently, you're to use the distance formula to determine the lengths of the sides of the triangle. Doing that, you would find ...
AB² = (6-4)² +(1 -6)² = 4 + 25
CB² = (6-1)² +(1-3)² = 25 + 4
At this point, it doesn't require much thought to realize these sides are the same length: √29.
I help! solve 12x^2+54x=-42
Answer: Hi!
Let's solve your equation step-by-step.
12x^2 + 54x = −42
Step 1: Subtract -42 from both sides.
12x^2 + 54x − (−42) = − 42 − (−42)
12x^2 + 54x + 42 = 0
Step 2: Factor left side of equation.
6(2x + 7)(x + 1) = 0
Step 3: Set factors equal to 0.
2x + 7 = 0 or x + 1 = 0
You have two answers.
x = −7/2 or x = −1
Hope this helps!
Which expression is equal to 7 times the sum of a number and 4
Answer:
7(n + 4)
Step-by-step explanation:
Represent the number by n. Then the verbal expression becomes
7(n + 4).
A projectile is fired vertically upward from a height of 300
300
feet above the ground, with an initial velocity of 900
900
ft/sec. Recall that projectiles are modeled by the function h(t)=−16t2+v0t+y0
h
(
t
)
=
−
16
t
2
+
v
0
t
+
y
0
. Write a quadratic equation to model the projectile's height h(t)
h
(
t
)
in feet above the ground after t seconds.
Step-by-step explanation:
It is given that, a projectile is fired vertically upward from a height of 300 feet above the ground, with an initial velocity of 900 ft/s.
The general equation with which a projectile are modled by the function is given by :
[tex]h(t)=-16t^2+v_ot+y_o[/tex]
y₀ is the initial height above the ground
v₀ = initial velocity
So,
[tex]h(t)=-16t^2+900t+300[/tex]
This is the quadratic equation that models the projectile height in feet above the ground after t seconds.
1. Approximate the given quantity using a Taylor polynomial with n3.
2. Compute the absolute error in the approximation assuming the exact value is given by a calculator.
Fourth underroot(94)
a. p3(94)
b. absolute error
Answer:
See the explanation for the answer.
Step-by-step explanation:
Given function:
[tex]f(x) = x^{1/4}[/tex]
The n-th order Taylor polynomial for function f with its center at a is:
[tex]p_{n}(x) = f(a) + f'(a) (x-a)+\frac{f''(a)}{2!} (x-a)^{2} +...+\frac{f^{(n)}a}{n!} (x-a)^{n}[/tex]
As n = 3 So,
[tex]p_{3}(x) = f(a) + f'(a) (x-a)+\frac{f''(a)}{2!} (x-a)^{2} +...+\frac{f^{(3)}a}{3!} (x-a)^{3}[/tex]
[tex]p_{3}(x) = f(a) + f'(a) (x-a)+\frac{f''(a)}{2!} (x-a)^{2} +...+\frac{f^{(3)}a}{6} (x-a)^{3}[/tex]
[tex]p_{3}(x) = a^{1/4} + \frac{1}{4a^{ 3/4} } (x-a)+ (\frac{1}{2})(-\frac{3}{16a^{7/4} } ) (x-a)^{2} + (\frac{1}{6})(\frac{21}{64a^{11/4} } ) (x-a)^{3}[/tex]
[tex]p_{3}(x) = 81^{1/4} + \frac{1}{4(81)^{ 3/4} } (x-81)+ (\frac{1}{2})(-\frac{3}{16(81)^{7/4} } ) (x-81)^{2} + (\frac{1}{6})(\frac{21}{64(81)^{11/4} } ) (x-81)^{3}[/tex]
[tex]p_{3} (x)[/tex] = 3 + 0.0092592593 (x - 81) + 1/2 ( - 0.000085733882) (x - 81)² + 1/6
(0.0000018522752) (x-81)³
[tex]p_{3} (x)[/tex] = 0.0092592593 x - 0.000042866941 (x - 81)² + 0.00000030871254
(x-81)³ + 2.25
Hence approximation at given quantity i.e.
x = 94
Putting x = 94
[tex]p_{3} (94)[/tex] = 0.0092592593 (94) - 0.000042866941 (94 - 81)² +
0.00000030871254 (94-81)³ + 2.25
= 0.87037 03742 - 0.000042866941 (13)² + 0.00000030871254(13)³ +
2.25
= 0.87037 03742 - 0.000042866941 (169) +
0.00000030871254(2197) + 2.25
= 0.87037 03742 - 0.007244513029 + 0.0006782414503 + 2.25
[tex]p_{3} (94)[/tex] = 3.113804102621
Compute the absolute error in the approximation assuming the exact value is given by a calculator.
Compute [tex]\sqrt[4]{94}[/tex] as [tex]94^{1/4}[/tex] using calculator
Exact value:
[tex]E_{a}[/tex](94) = 3.113737258478
Compute absolute error:
Err = | 3.113804102621 - 3.113737258478 |
Err (94) = 0.000066844143
If you round off the values then you get error as:
|3.11380 - 3.113737| = 0.000063
Err (94) = 0.000063
If you round off the values up to 4 decimal places then you get error as:
|3.1138 - 3.1137| = 0.0001
Err (94) = 0.0001
Find the slope of the line whose x-intercept is 4 and the y- intercept is -9
Answer:
y = (9/4)x - 9
Step-by-step explanation:
The x-intercept is (4, 0) and the y-intercept is (0, -9).
As we move from (0, -9) to (4, 0), x (the 'run' increases by 4 and y (the 'rise' increases by 9. Thus, the slope of the line connecting these two points is m = rise/run = 9/4, from which we can write the desired equation in the form y = mx + b:
y = (9/4)x - 9
The minute hand of a watch has a length of 1.4 cm. Find the; (a) distance moved by the tip of the minute hand from 8.13 am to 8.49 am. (b) angle swept by the minute hand if the tip moves 8.8 mm (c)time it will bee when the minute hand sweeps the angle calculated in (b), if the minute hand started moving at 8.39 am
Answer:
A). The distance covered= 5.2752 cm
B). Angle swept = 36°
C). The time = 8:45 am
Step-by-step explanation:
The watch is assumed to be a circle while the minute hand is assumed to be the radius
Radius = 1.4cm
A). From 8:13 to 8:49= 36 minutes
Recall, there is 60 minutes in a round watch.
The distance covered= 2πr*36/60
The distance covered= 2*3.14*1.4*0.6
The distance covered= 5.2752 cm
B). If distance covered is 8.8 mm
8.8 mm = 0.88cm
0.88= 2*3.14*1.4*(x/360)
0.88/(8.792)=x/360
0.1= x/360
0.1= x/360
36°= x
Angle swept = 36°
C). The time it will be if the watch started from 8:39 am and moved 36°
36/360= y/60
0.1= y/60
0.1*60= y
6 minutes= y
The time with be 8:39+6 minutes
The time = 8:45 am
