1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
PtichkaEL [24]
3 years ago
12

The mean of 12 numbers is 20 and the mean of another 8 numbers is 25 find the mean of the 20 numbers

Mathematics
1 answer:
AysviL [449]3 years ago
8 0

Answer:

22

Step-by-step explanation:

mean is calculated as

mean = \frac{sum}{count}

Given the mean of 12 numbers is 20 , then

\frac{sum}{12} = 20 ( multiply both sides by 12 )

sum = 240

Given the mean of 8 numbers is 25 , then

\frac{sum}{8} = 25 ( multiply both sides by 8 )

sum = 200

Total sum of the 20 numbers = 240 + 200 = 440, then mean of 20 numbers is

mean = \frac{440}{20} = 22

You might be interested in
Help please :) I will show the next questions in the other one so please answer them.
Yuki888 [10]

Answer:

Can you please take a better picture

Step-by-step explanation:

6 0
4 years ago
I need help is it A B C or D
kow [346]
I think its answer A
4 0
4 years ago
15 over 1000 wrote in scientific notation​
Katena32 [7]

Answer:

1.5*10^-2

Step-by-step explanation:

You mean 15/1000 written in scientific notation?

In this case, it would be- 1.5*10^-2.

3 0
3 years ago
Fantastic Middle School is building a park, in the shape of a square, with an area of 256 square feet. How much fence do they ne
frez [133]
A = a^2.....where " a " is the size of 1 side
A = 256

256 = a^2...take sqrt of both sides, eliminating the ^2
sqrt 256 = a
16 = a

so each side is 16 ft....now we find the perimeter
P = 4a....where " a " is the size of each side
P = 4(16)
P =  64.......so they will need 64 ft of fencing <===
6 0
3 years ago
A research scientist wants to know how many times per hour a certain strand of bacteria reproduces. The mean is found to be 13.6
dimaraw [331]

Answer:

The confidence interval is  13.4<  \mu < 13.8

Step-by-step explanation:

From the question we are told that

   The sample  mean is \= x  =  13.6

     The standard deviation is \sigma =  1.9

     The sample  size is  n  =  189

given that the confidence level is  85% then the level of significance is mathematically represented as

            \alpha = (100 - 85 )\%

            \alpha  =  0.15

Next we obtain the critical value  of \frac{\alpha }{2} from the normal distribution table  the value  is  

      Z_{\frac{\alpha }{2} } =  1.44

Generally the margin of error is mathematically represented as

        E =  Z_{\frac{\alpha }{2} } *  \frac{\sigma}{\sqrt{n} }

=>     E = 1.44*  \frac{1.9}{\sqrt{189} }

=>     E = 0.1990

The  85%  confidence interval is mathematically represented as  

        \= x  - E <  \mu

=>      13.6- 0.1990 <  \mu <  13.6+ 0.1990

=>      13.4<  \mu < 13.8

           

5 0
3 years ago
Other questions:
  • Nick's telephone company charges $0.07 per minute for weekend calls and $0.08 per minute for calls made on weekdays. This month
    14·1 answer
  • 4(1-3x)-14&gt;4(2x+3)-9x
    10·1 answer
  • Find the slope and y-intercept of the equation 4x+5y=-9
    7·1 answer
  • In 2000 there were 100 rabbits in Central Park the population increased by 16% each year ? Write a function to illustrate the si
    9·1 answer
  • victor has the map scale missing.he knows the distance from the lake to the youth center is 8 miles. on the map they are 2in. ap
    6·2 answers
  • Select the ratios that are equivalent to 3 boys and 5 girls
    5·1 answer
  • Expand and Simplify <br> 4( b+3) + 2 (b + 5)
    15·2 answers
  • Choose the fractions that are greater than 1/2.
    13·1 answer
  • Bab need someone who can do quick mafs please!
    15·2 answers
  • The temperature dropped 20 degrees from noon to midnight. The temperature at midnight was 24°F. Write and solve an equation to f
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!