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
dolphi86 [110]
2 years ago
7

on the last 5 quizzes, marco has earned a total of 21 out of 25 possible points. if he has a perfect score on the next several q

uizzes, exactly how many points will he need to bring up his average up to 90%
Mathematics
1 answer:
nevsk [136]2 years ago
6 0

Using the mean concept, it is found that we will need 15 more points to bring up his average up to 90%.

The mean of a data-set is the <u>sum of all observations divided by the number of observations</u>.

In this problem:

  • In the first 5 observations, total of 21 out of 25 points, hence the mean for these observations is \frac{21}{25} = 0.84.
  • In the next n observations, mean of 1.

Hence, the mean is:

M = \frac{0.84(5) + n}{5 + n} = \frac{4.2 + n}{5 + n}

We want the mean to be of 0.9, thus:

M = 0.9

\frac{4.2 + n}{5 + n} = 0.9

4.2 + n = 0.9n + 4.5

0.1n = 0.3

n = \frac{0.3}{0.1}

n = 3

3 more testes are need, each worth 5 points, hence, 15 more points are needed to bring up his average up to 90%.

A similar problem is given at brainly.com/question/25323941

You might be interested in
Estimate 34,182-18,717 by first rounding each number to the nearest thousand.
tresset_1 [31]

Answer:

15,000

Step-by-step explanation:

First, round both the numbers:

34,182 rounds down to 34,000

18,717 rounds up to 19,000

Subtract you're two rounded numbers

34,000 - 19,000 = 15,000

6 0
3 years ago
Let’s write the possible subsets of the following sets and list the proper subsets separately
Arisa [49]

Step-by-step explanation:

(a) subsets are {apple}, { }

(b) subsets are {1}, {2}, {1,2}, { }

proper subsets are {1}, {2}

(c) subsets are

{a}, {b}, {c}, {a,b}, {a,c}, {b,c}, {a,b,c}, { }

proper subsets are {a}, {b}, {c}, {a,b}, {a,c}, {b,c}

(d) subsets are {1},{2},{3},{4},{1,2},{1,3},{1,4},{2,3},{2,4},{3,4},{1,2,3},{1,2,4},{1,3,4},{2,3,4},{1,2,3,4},{ }

proper subsets are {1},{2},{3},{4},{1,2},{1,3},{1,4},{2,3},{2,4},{3,4},{1,2,3},{1,2,4},{1,3,4},{2,3,4}

3 0
2 years ago
By how much does 5 exceed -4?<br>(a) 1<br>(b)-1<br>(c) 9<br>(d) -9​
Elden [556K]

Answer:

C

Step-by-step explanation:

-4+9=5

6 0
3 years ago
Express each product in the simplest form. A. wx/6 B. wx/3 C. 2/3/wx D. wx
____ [38]

Answer:

A) \frac{wx}{6}

Step-by-step explanation:

\frac{3wx}{6x}\cdot \frac{3wx}{9w}

Multiply:

\frac{3wx\cdot \:3wx}{6x\cdot \:9w}

Cancel off the common factor "w":

\frac{3x\cdot \:3wx}{6x\cdot \:9}

Cancel off the common factor "x":

\frac{3\cdot \:3wx}{6\cdot \:9}

\frac{9wx}{54}

Cancel off the common factor "9":

\frac{wx}{6}

3 0
3 years ago
Kamden is a mind-reading alien. He had each friend draw and look at a card, then he guessed whether the card had a star on it.
earnstyle [38]

Answer:

what are u asking?

Step-by-step explanation:

6 0
3 years ago
Other questions:
  • Tiffany tried to solve an equation step by step.
    5·1 answer
  • A sample of 28 elements is selected to estimate a 95% confidence interval for the variance of the population. The chi-square val
    13·1 answer
  • Nicole wants to celebrate her 15th birthday at the Ice Skating Rink. They charge a $50 flat fee for birthday party rental and $1
    13·2 answers
  • at the zoo, there were 3 times as many monkeys as lions. Tom counted a total of 24 monkeys and lions. How many monkeys were ther
    10·1 answer
  • A circle of radius of 4 inches has an arc length of 5.8 inches. Find the measure of the central angle.
    15·1 answer
  • Which pair of variables has a clear causal link between the two named variables?
    5·1 answer
  • Please Help - Point <br> x^3-4x&lt;-5x^2+20<br> Solve in interval notation and list the zeros
    10·1 answer
  • What 2+3+5+6+7+8+9+10=
    6·2 answers
  • Help help math math math math
    8·1 answer
  • Please help and view image below!!
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!