There are 20 peoples in a singing group. The mean age of 12 of the members is 18years. The mean age of the remaining 8 is 23 years. What is the mean age of the 20 members of the singing group?​

Answers

Answer 1

Answer:

  20

Step-by-step explanation:

The sum of the ages of the first 12 is ...

  12×18 = 216

The sum of the ages of the remaining 8 is ...

  8×23 = 184

So, the sum of ages of all 20 people is ...

  216 +184 = 400

and their average age is ...

  400/20 = 20

The mean age of the members of the group is 20.

_____

The mean of a data set is the total of the values, divided by the number of values.


Related Questions

How to add or subtract this polynomial

Answers

Answer:

18x^2 + 9x - 5

Step-by-step explanation:

Combine like terms:

(9x^2-8) + (9x^2+9x+3)

= 9x^2 + 9x^2 + 9x - 8 + 3

= 18x^2 + 9x - 5

A child is laying on the ground relaxing and looking up at a plane that is passing by. If the plane’s altitude is 33,500 feet and the child’s eyes are located 8,200 feet away from a point on the ground directly beneath the plane, what is the angle of elevation for the child’s line of sight to the plane?

Answers

Answer:

  about 76.2°

Step-by-step explanation:

The geometry can be modeled by a right triangle with the given dimensions being the side opposite the angle (height = 33,500 ft) and the side adjacent to the angle (8,200 ft). The fact that you know these two sides suggests the inverse of the tangent function may be useful.

  Tan = Opposite/Adjacent

  tan(angle) = (33,500/8,200)

  angle = arctan (335/82) ≈ 76.246°

The angle of elevation is about 76.2°.

find the value of p in the following equation: 6 * 2/4 = p * 1/4

Answers

Answer: [tex]p=12[/tex]

Step-by-step explanation:

[tex]6*\frac{2}{4}=p*\frac{1}{4}[/tex]

Solve the multiplication on the left side.

6 and 4 can be simplified.

6/2=3

4/2=2

Leaving it like;

[tex]3*\frac{2}{2}=p*\frac{1}{4}[/tex]

2 and 2 is 1 and 3 times 1 is 3.

[tex]3=p*\frac{1}{4}[/tex]

Multiply by 4 to eliminate the fraction and isolate p.

[tex]4*3=p*\frac{1}{4}*4\\12=p[/tex]

Yuri computes the mean and standard deviation for the sample data set 12, 14, 9, and 21. He finds the mean is 14. His steps for finding the standard deviation are below.

s = StartRoot StartFraction (12 minus 14) squared + (14 minus 14) squared + (9 minus 14) squared + (21 minus 14) squared Over 4 EndFraction EndRoot. = StartRoot StartFraction negative 2 squared + 0 squared + negative 5 squared + 7 squared Over 4 EndFraction EndRoot. = StartRoot StartFraction 4 + 0 + 25 + 49 Over 4 EndFraction EndRoot. = StartRoot StartFraction 78 Over 4 EndFraction EndRoot. = StartRoot 19.5 EndRoot.

What is the first error he made in computing the standard deviation?
A. Yuri failed to find the difference between each data point and the mean.
B. Yuri divided by n instead of n -1.
C. Yuri did not subtract 9 - 14 correctly.
D. Yuri failed to square -2 correctly.

Answers

Answer:

B. Yuri divided by n instead of n-1

Step-by-step explanation:

It was stated in the question that the dataset was sample dataset. For a sample dataset, the standard deviation is given by the formula,

σ = √ Σ (Xi - mean)²/(n - 1) where i = 1,2,3.....n

Since this is just a sample dataset and not the whole population, Yuri should have divided by n-1 instead of n.

Answer:

B.

Step-by-step explanation:

(Here's Answers for the Quiz I did so far!)

1. Abby is collecting rainfall data.

Answer: B.

2. The Monthly Mean Salaries

Answer: A.

3. The Number of Cars at a Dealer Ship

Answer: A. (6.9)

4. The Mean Set of Credit Card Scores.

Answer: C. (720)

Which of the following expressions has the greatest value?
3^3 2^5 1^10 5^2

Answers

Answer:

2^5

Step-by-step explanation:

2^5 = 32

3^3=27

1^10 =1

5^2 = 25

Answer:

2^5

Step-by-step explanation:

Look at the attachment

Trust me,I will give braineist. I swear to god.

Answers

Answer:

= 1696m^3

Step-by-step explanation:

V = πr²h

= 3.14 x 6 x 6 x 15

= 3.14 x 540

= 1695.6 m^3

= 1696m^3

how are a common denominator and a common multiple alike and diferent

Answers

Answer:

To find a common denominator of two fractions, you have to find a number that both denominators of the given fractions will divide into. And to find a common multiple, you have to find a number that both given numbers will divide into.

Step-by-step explanation:

Answer:

To find a common denominator of two fractions, you have to find a number that both denominators of the given fractions will divide into. And to find a common multiple, you have to find a number that both given numbers will divide into.

Step-by-step explanation:

The typical amount of sleep per night that adults get has a bell-shaped distribution with a mean of 7.5 hours and a standard deviation of 1.3 hours. About 68% of adults typically sleep between a minimum of ___ hours a night and a maximum of ____ hours a night. Please enter your answer in the following format and round to the first decimal place: (min_value, max_value)

Answers

Answer:

(6.2, 8.8).

Step-by-step explanation:

The Empirical Rule states that, for a normally distributed(bell-shaped) random variable:

68% of the measures are within 1 standard deviation of the mean.

95% of the measures are within 2 standard deviation of the mean.

99.7% of the measures are within 3 standard deviations of the mean.

In this problem, we have that:

Mean = 7.5 hours

Standard deviation = 1.3 hours

About 68% ...

By the Empirical Rule, within 1 standard deviation of the mean.

7.5 - 1.3 = 6.2

7.5 + 1.3 = 8.8

So in the format requested

(6.2, 8.8).

PLS HELP ME!
Um doing venn digrams so u have to set one up for it to work... TWENTY POINTS

Answers

Answer:

Creating a diagram..

Step-by-step explanation:

Alrighty, I've made a diagram. I've even uploaded it so everyone can see how good at drawing I am (not)

a. 7 do not own anything.

b. the probability that someone owns a bone or a stick is 50%.

c. the probability that someone owns a rock and a bone is 14%.

d. the probability that someone owns at least 2 items is 42%.

e. the probability that someone owns only 1 of these items is 51%.

Please tell me if im wrong! im only a student .m.

Kelly needs 1/8 cups of sugar to make 1/4 of her cookie recipe. How much sugar does she need to make the entire recipe?

Answers

Answer:

1/2 cup of sugar

Step-by-step explanation:

She needs to multiply 1/8 cup of sugar by 4 to make the entire recipe since 18 cup of sugar is only good for a fourth of the recipe.

Find the volume of a right circular cone that has a height of 12 cm and a base with a diameter of 18 cm.

Answers

Answer:1017.36 cm^3

Step-by-step explanation:

Diameter=18cm

Radius=r=18/2=9cm

Height=h=12cm

Volume of cone=1/3 x π x r^2 x h

Volume of cone=1/3 x 3.14 x 9^2 x 12

Volume of cone=1/3 3.14 x 9 x 9 x 12

Volume =(1x3.14x9x9x12) ➗ 3

Volume =3052.08 ➗ 3

Volume =1017.36

Volume of cone=1017.36 cm^3

What’s the correct answer for this?

Answers

Answer:

D: 8 and 2 and then 8 and 6.

Step-by-step explanation:

Corresponding angles are angles in the same position at an intersection of lines. For example, some of the corresponding angles in this picture are 1 and 7, and 8 and 2. Alternate interior angles are angles that are on the opposite sides of a transversal but are on the inner sides. For example, 8 and 6 and 7 and 5. If you look at all the options and use process of elimination, D will be the only possible answer. For A, 1 and 2 are not corresponding angles, as they are on opposite sides of the same line. For B, 4 and 6 are not alternate interior angles. They are vertical angles, congruent angles mirrored on the opposite side. For C, 7 and 2 are not corresponding angles, as they are not in the same relative position. Therefore, D is the only answer left. 8 and 2 are corresponding angles: they are both on the right side of the lines next to them. 8 and 6 are alternate interior angles, since they are on the opposite sides of the line, but on the inside.

-3b+7=13 solve for b

Answers

Answer:

b = -2

Step-by-step explanation:

Start with your given:

-3b + 7 = 13

Subtract 7 on both sides:

-3b = 6

Then, divide -3 on both sides and solve:

b = -2

Answer:

b = -2

Step-by-step explanation:

You start by subtracting the 7 on the left and move it to the other side. Then you have 6 on the right and -3b on the left. Then you divide the -3 on each side and that gives you b= -2.

Hope this helps.


A bookstore had 60 copies of a magazine. Yesterday, it sold 1/3 of them. Today, it sold 1/4 of what remained. How many copies does the bookstore have left?

Answers

Answer:

30

Step-by-step explanation:

1/3 of 60 is 20

40 would be left

1/4 of 40 is 10 so 30 would be left

The table shows the number of cups of water required when cooking different amounts of rice.

Amount of
Rice
(cups) Amount of
Water
(cups)
2 5
3 7.5
5 12.5
8 20
Which statements apply to the ratio of rice and water? Choose two options.

The amount of rice is the dependent value.
The amount of water is the dependent value.
The amount of rice is the independent value.
The amount of water is the independent value.
The values cannot be labeled as dependent or independent without a given equation

Answers

Answer:

The amount of water is the dependent value.The amount of rice is the independent value.

Step-by-step explanation:

The wording "the amount of water required for different amounts of rice" suggests that the "output" value of the table is the amount of water, and the "input" value is the amount of rice.

That makes "water" the dependent variable, and "rice" the independent variable.

  The amount of water is the dependent value.

  The amount of rice is the independent value.

Answer:

The amount of water is the dependent value.

The amount of rice is the independent value.

Step-by-step explanation:

Jason earned $54 at his job when he worked for 4 hours. What was his hourly pay rate in hours per dollar?

Answers

Answer:

$13.50

Step-by-step explanation:

$54 divided by 4 is $13.50.

what's the solution to the inequality 1 2/3 > r - 7/12​

Answers

Answer:

r ≤ 2 1/4

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDASEquality PropertiesRewriting Fractions

Step-by-step explanation:

Step 1: Define

1 2/3 ≥ r - 7/12

Step 2: Solve for r

Rewrite:                    5/3 ≥ r - 7/12Isolate r:                    9/4 ≥ rRewrite:                    r ≤ 9/4Reduce:                    r ≤ 2 1/4

Here we see that any number r less than or equal to 2 1/4 will work as a solution to the inequality.

What's your real rate of return if your savings account pays 2.5% interest and inflation is at 1%?
A. 1.5%
B. 2.5%.
C. 3.5%
D. Can't calculate.

Answers

Answer:

Real rate of return = 1.5%

Step-by-step explanation:

Given:

Savings account return = 2.5%

Inflation rate = 1%

Find:

Real rate of return = ?

Computation:

⇒ Nominal rate  of return = Real rate of return + Inflation rate

⇒ Real rate of return = Savings account return - Inflation rate

⇒ Real rate of return = 2.5% - 1%

⇒ Real rate of return = 1.5%

Write an equation that is parallel to the line y=3x-5 and passes through the point (-1,2)

Answers

Two lines with same slopes are parallel.
So The slope must be 3.
2=3(-1)+a
a=5
y=3x+5

40/27 ,20/9, 10/3 what is the next term in the geometric sequence ?

Answers

Answer:

5/1

Step-by-step explanation:

40/27

20/9

10/3

5/1

divided by 2 and 3 each other!

The (average) sales price for single family property in Seattle and Port Townsend is tabulated below.



Year Seattle Port Townsend


1970 $38,000 $8,400


1990 $175,000 $168,400



Find a linear model relating the year x and the sales price y for a single family property in Seattle.

Answers

Answer:

[tex]y=6,850x - 13,456,500[/tex]

Step-by-step explanation:

To find the linear model, we need to find a linear equation, where its slope is defined as

[tex]m=\frac{y_{2} -y_{1} }{x_{2}-x_{1} }[/tex]

So, we use the given points (1970, 38000) and (1990, 175000), to find the slope

[tex]m=\frac{175,000-38,000}{1990-1970}=\frac{137,000}{20} =6,850[/tex]

Now, we use the point-slope formula to find the equation

[tex]y-y_{1} =m(x-x_{1} )\\y-38000=6850(x-1970)\\y=6850x-13,494,500+38,000\\y=6,850x - 13,456,500[/tex]

Therefore, the linear model is

[tex]y=6,850x - 13,456,500[/tex]

Fifteen mothers were asked how many months old their babies were when they cut their first tooth. The results are shown below.

8, 8, 6, 8, 9, 10, 5, 7, 9, 5, 9, 7, 6, 8, 7

Find the range and the outlier(s), if any, of the data set.

Answers

range 5
there are no outliers

Which of the following is a ray as shown in the drawing?

Answers

Answer:

DH

Step-by-step explanation:

this is just to comment to tell everyone this is multiple choice meaning it could be ad or ij togethe.

50 POINTS!!!!!!! WILL MARK BRAINLIEST! NO COPY/PASTE! TWO TO THREE SENTENCES AND EXPLAIN! WILL REPORT STUPID ANSWERS! According to Nikita Khrushchev, Premier of the Soviet Union, which of the three events had the potential to advance Soviet interests the most? The three events are the Cuban Missile Crisis, The Space Race, and The Berlin Wall.

Answers

Answer: Soviet leader Nikita Khrushchev had gambled on sending the missiles to Cuba with the specific goal of increasing his nation's nuclear strike capability.

Step-by-step explanation:

The Soviet Union signed a treaty with Hitler, the U.S. kept the atomic bomb a secret, and the U.S. took a long time to attack Hitler. France, Britain, and the United States wanted to reunify Germany, so they combined their areas into West Germany. Soviets cut off transportation to West Berlin. This lead to the United States and Britain using the Berlin airlift to bring food/supplies into the isolated part of Soviet occupied West Berlin.

If AB = 10, what is the length of DE?
11
5
12
3


Answers

Answer:

11

Step-by-step explanation:

Answer:

11

Step-by-step explanation:

Two forces are acting on an object at the same point. Determine the angle between the two forces. (-2,7) and (3,-1)

Answers

The answer is 56 degree

Answer:

It is 124 degrees.

Step-by-step explanation:

You square each coordinate like this:

sqrt(x^2+y^2 )

You will end up getting sqrt(53 and sqrt(10.

Then find the dot product which is -6+-7=-13.

Then cos^-1(-13/sqrt53*sqrt10)

=124 degrees

3.5.49 X 0.67 *
Your answer
What is the answer

Answers

Answer:

2.37783 or 23.7783

Step-by-step explanation:

A rectangular poster has a length of 24 inches , and it’s width is 12 inches. What is the perimeter of the poster.

Answers

Answer:

(24 + 12) x 2 = 72 inches


What percentage of students who take honors English are taking a non-honors math class?

Answers

Answer:

B

Step-by-step explanation:

Took quiz GL

Answer:

the answer is not B

Step-by-step explanation:

the answer is A I actually took the quiz


Two part-time employees share one full-time job. A girl works Mondays. Thursday, Wednesdays, and Fridays, and a boy works Tuesdays. The job pays an annual salary of $28,612. What annual salary does each employee earn?
The girls salary is______

Answers

One year is 52 week, days of work is 5, 5*52 week is 260 days. One year salary is 28,612, use 28,612/ 260 =110.05 a day. If the boy works only one day a week the he only work 52 day in a year, so is 52*110.05=5722.4 for the boys.
Then use 28612-5722.4= 22889.60 is the girls salary
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