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
Sauron [17]
3 years ago
13

The mean of four numbers is 70. When a fifth number is included, the mean of the five numbers is 80. What is the fifth number?

Mathematics
1 answer:
Yakvenalex [24]3 years ago
3 0
<h3>Answer: 120</h3>

=============================================

Explanation:

S = sum of the first four values

S/4 = 70 since we divide the sum by 4 to get the mean of the first four values

S = 280 is the result after multiplying both sides by 4

Let x be the fifth unknown value. Adding it onto S leads to S+x = 280+x. This represents the sum of all five values.

Dividing that sum 280+x over 5 leads to the new mean 80, which leads to...

----------

(280+x)/5 = 80

280+x = 5*80

x+280 = 400

x = 400-280

x = 120

The fifth number is 120

You might be interested in
6. Rosanne is selling her Corvette. She wants to include a photo of her
Likurg_2 [28]

Answer:

add them

Step-by-step explanation:

you have to add them all up because it says find the range

6 0
2 years ago
A veterinarian estimated the weight of a puppy to be 7 kg. The actual weight of the puppy was 6.6 kg.
KIM [24]

9514 1404 393

Answer:

  • absolute error: 0.4 kg
  • relative error: 6.1%

Step-by-step explanation:

The absolute error is the difference between the estimate and the actual weight:

  7.0 kg -6.6 kg = 0.4 kg . . . . absolute error

__

The relative error is the ratio of the absolute error to the actual weight:

  (0.4 kg)/(6.6 kg) × 100% = 6.060606...% ≈ 6.1% . . . . relative error

6 0
3 years ago
In 1985, there were 285 cell phone subscribers in Arlington. The number of subscribers increased by 75% per year since 1985. Fin
ANTONII [103]

Answer:

The number of subscribers in 2008 is 110,845,988

Step-by-step explanation:

The number of cell phone subscribers in Arlington, in t years after 1985, can be modeled by the following equation.

N(t) = N(0)(1+r)^{t}

And which N(0) is the number of subscribers in 1985 and r is the rate it increases per year, as a decimal.

In 1985, there were 285 cell phone subscribers in Arlington.

This means that N(0) = 285

The number of subscribers increased by 75% per year since 1985.

This means that r = 0.75

So

N(t) = 285(1.75)^{t}

Find the number of subscribers in 2008.

2008 is 2008-1985 = 23 years after 1985. So we have to find N(23).

N(23) = 285(1.75)^{23} = 110,845,988

The number of subscribers in 2008 is 110,845,988

8 0
3 years ago
3. Which ordered pair is a solution of the equation y = x – 2? (1 point) (3, 1) (1, 3) (–1, 3) (3, –1)
kozerog [31]
The answer is (3,1)
7 0
3 years ago
I am confused please can you help me
lorasvet [3.4K]
Domain x|x = -2, 2
range x|x = -1, 4
8 0
3 years ago
Other questions:
  • Simplify. (½) ²− 6(2−2/3)
    14·1 answer
  • 2. A researcher collected data about the favorite car color of a particular population. He asked 250 people about their favorite
    15·1 answer
  • You draw five cards at random from a standard deck of 52 playing cards. What is the probability that the hand drawn is a full ho
    13·1 answer
  • The number of turtles in a pond is four more than twice the number of crocodiles.
    8·2 answers
  • Which best describes bias, if any, from the sample surveyed? survey: favorite sports sample: randomly selected fans at a basebal
    9·1 answer
  • If 2(x - 5) + 3(x - 5) = 10, what is the value of x - 5?
    5·2 answers
  • Simplify 3(x+7)-2(4x-3)=
    15·2 answers
  • A turtle is 20 5/6 inches below the surface of the pond. It dives to a depth of 32 1/4. What is the change of the turtles posist
    10·1 answer
  • Help please :) On a small island, scientists observed and graphed changes in wolf and moose populations. From 1965 to 1970, whic
    8·1 answer
  • Complete the equation of the line through (-10,-7)(−10,−7)left parenthesis, minus, 10, comma, minus, 7, right parenthesis and (-
    10·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!