Answer:
455 ways
Step-by-step explanation:
Given
[tex]n = 15[/tex] --- friends
[tex]r = 3[/tex] -- available postcard kinds
Required
Ways of sending the cards
The question is an illustration of combination and the formula is:
[tex]^nC_r = \frac{n!}{(n - r)!r!}[/tex]
So, we have:
[tex]^{15}C_3 = \frac{15!}{(15 - 3)!3!}[/tex]
[tex]^{15}C_3 = \frac{15!}{12!*3!}[/tex]
Expand
[tex]^{15}C_3 = \frac{15*14*13*12!}{12!*3*2*1}[/tex]
[tex]^{15}C_3 = \frac{15*14*13}{3*2*1}[/tex]
[tex]^{15}C_3 = \frac{2730}{6}[/tex]
[tex]^{15}C_3 = 455[/tex]
help i’ll give brainliest please hurry
Find the value of x in each case:
How to answer this question
Answer:
(0.3049 ; 0.3751)
Step-by-step explanation:
The confidence interval for proportion can be obtained using the relation :
Phat ± Zcritical * [√phat(1-phat) / n]
phat = x / n
Sample size, n = 700
x = 238
phat = 238/700 = 0.34
Zcritical at 95% = 1.96
C.I = 0.34 ± 1.96 * [√0.34(1-0.34) / 700]
C.I = 0.34 ± 1.96 * 0.0179045
C. I = 0.34 ± 0.0350928
Lower boundary = 0.34 - 0.0350928 = 0.3049
Upper boundary = 0.34 + 0.0350928 = 0.37509
(0.3049 ; 0.3751)
What is the gradient of the blue line?
5
4
3
2
1
-5 -4 -3 -2 - 1 0 1. 2. 3. 4. 5
- 1
- 2
- 3
- 4
- 5
The line starts at (-5,3) and finishes (5,0.5)
Answer:
The gradient is -0.25
Step-by-step explanation:
Given
[tex](x_1,y_1) = (-5,3)[/tex]
[tex](x_2,y_2) = (5,0.5)[/tex]
Required
The gradient (m)
This is calculated as:
[tex]m = \frac{y_2 - y_1}{x_2 - x_1}[/tex]
So, we have:
[tex]m = \frac{0.5-3}{5--5}[/tex]
[tex]m = \frac{-2.5}{10}[/tex]
[tex]m = -0.25[/tex]
An 8-oz bottle of hair spray costs $4.46. Find the unit price in cents per ounce
Answer:
55.75 cents per ounce
Step-by-step explanation:
Take the cost and divide by the number of ounces
We want cents per ounce so change dollars to cents
446 / 8
55.75 cents per ounce
Can someone help me with this problem?
This Bar Chart shows the number of DVDs sold at a local music store during one week.
Which measure(s) of central tendency can be used to determine the average number of DVDs sold each day?
A. the median
B. the mean
C. the mean and the median
D. the mode
Answer:
B. the mean
Step-by-step explanation:
According to the Bar Chart shown, the number of DVDs sold at a local music store during one week are displayed.
Therefore, the measure(s) of central tendency that can be used to determine the average number of DVDs sold each day is the mean.
This is because the mean is the sum total of the number of DVDs sold, divided by the number, which gives the average.
Answer:
The Mean
Step-by-step explanation:
I took the test
kxndjdkdkdkkdkskskdkdjdjdjskskskdjdjddjd
Answer:
Not a functionFunctionFunctionNot a functionNot a functionHope this helps!
The distribution of the number of apples trees a farmer can plant each day is bell-shaped and has a mean of 62 and a standard deviation of 8. Use the empirical rule to help you answer the following. What is the approximate percentage of trees planted between 38 and 68
Answer:
The empirical rule, the approximate percentage of trees planted between 38 and 68 is 99.7%.
Step-by-step explanation:
The Empirical Rule states that, for a normally distributed random variable:
Approximately 68% of the measures are within 1 standard deviation of the mean.
Approximately 95% of the measures are within 2 standard deviations of the mean.
Approximately 99.7% of the measures are within 3 standard deviations of the mean.
In this problem, we have that:
Mean of 62, standard deviation of 8.
What is the approximate percentage of trees planted between 38 and 86?
38 = 62 - 3*8
86 = 62 + 3*8
So within 3 standard deviations of the mean, which, by the empirical rule, the approximate percentage of trees planted between 38 and 68 is 99.7%.
A trough is 10 ft long and its ends have the shape of isosceles triangles that are 4 ft across at the top and have a height of 1 ft. If the trough is being filled with water at a rate of 15 ft3/min, how fast is the water level rising when the water is 8 inches deep
Answer:
7.5 ft³/min
Step-by-step explanation:
Let x be the depth below the surface of the water. The height, h of the water is thus h = 10 - x.
Now, the volume of water V = Ah where A = area of isosceles base of trough = 1/2bh' where b = base of triangle = 4 ft and h' = height of triangle = 1 ft. So, A = 1/2 × 4 ft × 1 ft = 2 ft²
So, V = Ah = 2h = 2(10 - x)
The rate of change of volume is thus
dV/dt = d[2(10 - x)]/dt = -2dx/dt
Since dV/dt = 15 ft³/min,
dx/dt = -(dV/dt)/2 = -15 ft³/min ÷ 2 = -7.5 ft³/min
Since the height of the water is h = 10 - x, the rate at which the water level is rising is dh/dt = d[10 - x]/dt
= -dx/dt
= -(-7.5 ft³/min)
= 7.5 ft³/min
And the height at this point when x = 8 inches = 8 in × 1 ft/12 in = 0.67 ft is h = (10 - 0.67) ft = 9.33 ft
The volume, V, of a sphere in terms of its radius, r, is given by , V(r)=4/3(pie)r^3. Express r as a function of V, and find the radius of a sphere with volume of 150 cubic feet. Round your answer for the radius to two decimal places.
r(V)=
A sphere with volume 150 cubic feet has radius
_________ feet.
Step-by-step explanation:
If
[tex]V=\dfrac{4\pi}{3}r^3[/tex]
then we can solve for r as
[tex]r = \sqrt[3]{\dfrac{3V}{4\pi}}[/tex]
If the volume of the sphere is 150 ft^3, then the radius is
[tex]r = \sqrt[3]{\dfrac{3(150\:\text{ft}^3)}{4\pi}} = 3.30\:\text{ft}[/tex]
The radius of the given sphere with a volume of 150 cubic feet is 2.29 feet, correct to two decimal places.
Given that
the volume of a sphere = 150 cubic feet.
the radius of the sphere=????
what is a Sphere?a round solid figure, or its surface, with every point on its surface equidistant from its center.
as we know,
the volume of a sphere
[tex]V=\frac{4}{3} *\pi *r^3[/tex]
[tex]r = \sqrt[3]{\frac{3V}{4\pi } }[/tex][tex]r = \sqrt[3]{\frac{3*150}{4\pi } }[/tex][tex]=2.29 feet[/tex]
therefore, the radius of the given sphere is 2.29feet
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A movie theater has a seating capacity of 283. The theater charges $5.00 for children, $7.00 for students, and $12.00 of adults. There are half as many adults as there are children. If the total ticket sales was $ 2060 on a sold out night, how many children, students, and adults attended
Answer: adults = 79
children = 158
student = 46
Step-by-step explanation:
Let a = adults
Let c = children
Let s = student
From the information given,
a + c + s = 283 ....... i
c/a = 2, c = 2a ....... ii
5c + 7s + 12a = 2060 ...... iii
Put the value of c = 2a into equation i
a + c + s = 283
a + 2a + s = 283
3a + s = 283
s = 283 - 3a
Note that c = 2a
From equation iii
5c + 7s + 12a = 2060
5(2a) + 7(283 - 3a) + 12a = 2060
10a + 1981 - 21a + 12a = 2060
10a + 12a - 21a = 2060 - 1981
a = 79
Note c = 2a
c = 2 × 79 = 158
Since a + c + s = 283
79 + 158 + s = 283
s = 283 - 237
s = 46
adults = 79
children = 158
student = 46
Rajah / Diagram 5 (b) Dalam Rajah 6, PQ ialah tangen sepunya dua bulatan. AQ dan BQ ialah tangen bagi bulatan yang masing-masing berpusat E dan F. Cari nilai x dan y. In Diagram 6, PQ is the common tangent of two circles. AQ and BQ is the tangent to the circles with centre E and F respectively. Find the value of x and y. [3 markah.
Answer:
36281629273781646181993836619946527189119292937467482919198$7473828191927364732818919283838292927383883829118661552621718919191019284746617171819001187373765252728
Step-by-step explanation:
173899918377+28910873638282
* Insert a digit to make numbers that are divisible by 6 if it is possible:
234_6
Answer:
i put in 3 to make 23436 because 36 is divisible by 6
Find the measure of angle C of a triangle ABC, if angle A=a and angle B= 2a.
*The answer is not 180-3a
The angle C of the triangle ABC is ( π - 3a ).
What is an angle?The angle is defined as the span between two intersecting lines or surfaces at or close to the point where they meet.
The angle will be calculated as follows:-
We know that the sum of the angles of the triangle is 180 degrees or π in radians.
∠A + ∠B + ∠C = π
a + 2a + ∠C = π
∠C = π - a - 2a
∠C = π - 3a
Therefore angle C of the triangle ABC is ( π - 3a ).
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Which of the following equations describes this graph?
A. y=(x-1)^2-
B. y=(x-3)^2+2
C. y=(x+1)^2-2
D. y=(x-2)^2+3
Answer:
The choose (A)
y=(x-1)²-2
Jerome is cooking dinner. He needs 8 ounces of broccoli for each person. Part A: Jerome is not sure how many people will come to dinner. Write an expression with a variable that represents the amount of broccoli Jerome needs for dinner. Identify what the variable represents. Part B: If Jerome has 32 ounces of broccoli, how many people can he feed? Create an equation and show all work to solve it.
Answer:
A. 8x = amount of broccoli needed
B. 4 people; 32÷8=4
Step-by-step explanation:
A. the variable (x) represents the amount of people.
B. 32 ounces divided by 8 ounces is enough for four people.
Find the solution for this system of equations.
2x + 4y = 8
x = 3y − 6
Answer:
[tex]{ \tt{2x + 4y = 8 - - - (a)}} \\ { \tt{x = 3y - 6 - - - (b)}} [/tex]
Substitute for x in equation (a) :
[tex]{ \tt{2(3y - 6) + 4y = 8}} \\ { \tt{6y - 12 + 4y = 8}} \\ { \tt{10y = 20}} \\ y = 2[/tex]
Substitute for y in equation (b) :
[tex]{ \tt{x = (3 \times 2) - 6}} \\ x = 0[/tex]
2x+4y =8
x=3y-6 ——> x–3y=–6
x–3y = – 6 ] ×(–2) ——> –2x +6y=12
2x+4y=8
–2x+6y =12
__o_o____
0+10y=20 —> 10y= 20 —> y= 20/10 —> y= 2
2x+4y=8 —> 2x + 4(2) = 8 —> 2x + 8=8 —> 2x = 0 —> x=0
(x,y) —> (0,2)
PLEASE HELP I DONT NEED EXPLANATION JUST THE EQUATION IM IN A TEST RN HELP ASAP THANK YOU SO MUCH :)))
Answer:
[tex]-x^{2}[/tex]
Step-by-step explanation:
It simple really its just a reflection over the x-axis making it a negative towards the parent function
Answer:
The answer is -x²
Step-by-step explanation:
Hope this helps :)
alvin is 5 years older than elga. the sum of their age is 85. what is elga age
Answer:
40 years old.
Step-by-step explanation:
We can let Elga's age equal [tex]x[/tex]. Alvin's age can be equal to [tex]y[/tex]. We can make several equations from the information we know. We know that Elga's age plus five equal's Alvin's age.
[tex]x+5=y[/tex]
We also know that the sum of their ages is 85.
[tex]x+y=85[/tex]
We can substitute [tex]x+5[/tex] for [tex]y[/tex] in the second equation since [tex]x+5=y[/tex], so we have the following equation:
[tex]x+(x+5)=85[/tex]
We can combine like terms to get
[tex]2x+5=85[/tex]
Subtracting 5 from both sides results in
[tex]2x=80[/tex]
After that, we can divide both sides by 2 to get
[tex]x=40[/tex]
Thus, Elga is 40 years old.
Answer:
e = 40
a=45
Step-by-step explanation:
a + e = 85
a = e+5
e + 5 + e = 85
2e = 80
e = 40
a=45
An arch is in the form of a parabola given by the function h = -0.06d^2 + 120, where the origin is at ground level, d meters is the horizontal distance and h is the height of the arch in meters.
Graph this function on your graphing calculator then complete the following statements.
The height of the arch is: ------- m
The width to the nearest meter, at the base of the arch is ------ m
Answer:
See attachment for graph
The height of the arch is: 120 m
The width to the nearest meter, at the base of the arch is 22 m
Step-by-step explanation:
Given
[tex]h = -0.06d^2 + 120[/tex]
Solving (a): The graph
See attachment for graph
Variable h is plotted on the vertical axis while variable d is plotted on the horizontal axis.
Solving (b): The height
The curve of [tex]h = -0.06d^2 + 120[/tex] opens downward. So, the maximum point on the vertical axis represents the height of the arch,
Hence:
[tex]height = 120[/tex]
Solving (c): The width
The curve touches the horizontal axis at two different points.
[tex]x_1 = -11[/tex]
[tex]x_2 = 11[/tex]
The absolute difference of both points represents the width.
So:
[tex]Width = |x_2 - x_1|[/tex]
[tex]Width = |11 - -11|[/tex]
[tex]Width = |11 +11|[/tex]
[tex]Width = |22|[/tex]
Hence:
[tex]Width = 22[/tex]
Suppose these data show the number of gallons of gasoline sold by a gasoline distributor in Bennington, Vermont, over the past 12 weeks.
Week Sales (1,000s of gallons)
1 17
2 22
3 20
4 24
5 18
6 17
7 21
8 19
9 23
10 21
11 16
12 23
(a) Using a weight of
1
2
for the most recent observation,
1
3
for the second most recent observation, and
1
6
for third most recent observation, compute a three-week weighted moving average for the time series. (Round your answers to two decimal places.)
Compute four-week and five-week moving averages for the time series.
Week Time Series Moving
Value Average Forecast
1 17
2 22
3 20
4 24
5 18
6 17
7 21
8 19
9 23
10 21
11 16
12 23
(b) Compute the MSE for the four-week moving average forecasts. (Round your answer to two decimal places.)
Compute the MSE for the five-week moving average forecasts. (Round your answer to two decimal places.)
(c) What appears to be the best number of weeks of past data (three, four, or five) to use in the moving average computation? MSE for the three-week moving average is 11.12.
Answer:
Use suitable identity to find the product (3-2x)(3+2x).Find the remainder when x³+ 3x²+3x+1 is divided by x+1.On a plane surface we can find straight lines.8√15 + 2√3The decimal form of 36 100(a-b)³ = a ³- ........ 3 + 3ab²-b³In the Cartesian plane the horizontal line is called .........The coefficient of x² in 2-x²+ x³ is -1.√225 is an irrational number.The coordinates of a point on x-axis is (y, 0).The coordinates of a point on x-axis is (y, 0).The coordinates of a point on x-axis is (y, 0).The coordinates of a point on x-axis is (y, 0).
Last year there were two hundred and forty seven thousand, three hundred and seventy two weddings in the UK.
Write this as a number
Answer:
247372
Step-by-step explanation:
two hundreds forty seven thousand, three hundred and seventy two
The number of weddings in the UK in numerical form will be 247,372.
What is Algebra?Algebra is the study of abstract symbols, while logic is the manipulation of all those ideas.
The acronym PEMDAS stands for Parenthesis, Exponent, Multiplication, Division, Addition, and Subtraction. This approach is used to answer the problem correctly and completely.
Last year there were two hundred and forty-seven thousand, three hundred and seventy-two weddings in the UK.
Convert the statement into a number. Then we have
⇒ 247,372
The number of weddings in the UK in numerical form will be 247,372.
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Solve the inequality and write the solution set using both set-builder notation and interval notation. -3a-15≤-2a+6
Answer:
[tex]\{a[/tex] ∈ [tex]R\ -21 \le a \le \infty \}[/tex] --- set builder
[tex][-21,\infty)[/tex] --- interval notation
Step-by-step explanation:
Given
[tex]-3a - 15 \le -2a + 6[/tex]
Required
Solve
Collect like terms
[tex]-3a + 2a \le 15 + 6[/tex]
[tex]-a \le 21[/tex]
Divide by -1
[tex]a \ge - 21[/tex]
Rewrite as:
[tex]-21 \le a[/tex]
Using set builder
[tex]\{a[/tex] ∈ [tex]R\ -21 \le a \le \infty \}[/tex]
Using interval notation, we have:
[tex][-21,\infty)[/tex]
The population of retired citizens in Minneapolis is 86700. If the population increases at a rate of 8.9% each year. What will the population of retirees be in 7 years? Write an exponential growth model for the future population P(x) where r is in years: P(x) = What will the population be in 7 years? (Round to nearest person)
Answer:
157,476 people
Step-by-step explanation:
the formula :
P(x) = 86700. (1+ 0.089)^r
for r = 7
=> P(x) = 86700 × (1+ 0.089)^7
= 86700 × (1.089)^7
= 86700 × 1.8163
= 157,476 people
On dividing 12x³ by 4x the quotient is …..
Answer:
12x^3 is equivalent to
12x*12x*12x which if we multiply is
1728x
we divide by 4x
1728x divided by 4x=432x
Hope This Helps!!!
Answer:
3x^2
Step-by-step explanation:
when u divide 12x^3/4x....u divide 12/4=3 along with the x also..tat is x^3/x=x^2
find the place value of 1 in 382619.
Answer:
Place value of 1 = 1 × 10 = 10
Step-by-step explanation:
In 382619,
Place of 1 = Tens
Place value of 1 = 1 × 10 = 10
A line contains the points (3,1) and (-6,4) what is the equation for this line in slope intercept form
Answer:
y = (-1/3)x + 2
Step-by-step explanation:
Since points (3,1) and (-6,4) lie on y = (-1/3)x + c , it should satisfy the this equation. Thus, intercept is 2.
Answer:
m = -⅓
Step-by-step explanation:
m = (y2- y1)/(x2 - x1)
m = (4 -1)/(-6-3)
m = -⅓
what are the coordinates of the point that is 1/6 of the way from a(14 -1) to b(-4 23)
9514 1404 393
Answer:
(11, 3)
Step-by-step explanation:
That point is ...
P = a + (1/6)(b -a) = (5a +b)/6
P = (5(14, -1) +(-4, 23))/6 = (70-4, -5+23)/6 = (11, 3)
The point of interest is (11, 3).
Answer:
The coordinates of the point that is 1/6 of the way from a to b is thus (11, 3)
Step-by-step explanation:
Let's look first at the x coordinates of the two given points: 14 and -4. From 14 to -4 is a decrease of 18. Similarly, from y = -1 to y = 23 is an increase of 24.
Starting at a(14, -1) and adding 1/6 of the change in x, which is -18, we get the new x-coordinate 14 + (1/6)(-18), or 14 - 3, or 11. Similarly, adding 1/6 of the increase in y of 24 yields -1 + 4, or 3.
The coordinates of the point that is 1/6 of the way from a to b is thus (11, 3)
Suppose 46% of politicians are lawyers. If a random sample of size 662 is selected, what is the probability that the proportion of politicians who are lawyers will differ from the total politicians proportion by less than 4%
Answer:
0.9606 = 96.06% probability that the proportion of politicians who are lawyers will differ from the total politicians proportion by less than 4%
Step-by-step explanation:
To solve this question, we need to understand the normal probability distribution and the central limit theorem.
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.
Central Limit Theorem
The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]
Suppose 46% of politicians are lawyers.
This means that [tex]p = 0.46[/tex]
Sample of size 662
This means that [tex]n = 662[/tex]
Mean and standard deviation:
[tex]\mu = p = 0.46[/tex]
[tex]s = \sqrt{\frac{p(1-p)}{n}} = \sqrt{\frac{0.46*0.54}{662}} = 0.0194[/tex]
What is the probability that the proportion of politicians who are lawyers will differ from the total politicians proportion by less than 4%?
p-value of Z when X = 0.46 + 0.04 = 0.5 subtracted by the p-value of Z when X = 0.46 - 0.04 = 0.42. So
X = 0.5
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
By the Central Limit Theorem
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{0.5 - 0.46}{0.0194}[/tex]
[tex]Z = 2.06[/tex]
[tex]Z = 2.06[/tex] has a p-value of 0.9803
X = 0.42
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{0.42 - 0.46}{0.0194}[/tex]
[tex]Z = -2.06[/tex]
[tex]Z = -2.06[/tex] has a p-value of 0.0197
0.9803 - 0.0197 = 0.9606
0.9606 = 96.06% probability that the proportion of politicians who are lawyers will differ from the total politicians proportion by less than 4%
