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
natka813 [3]
3 years ago
14

Please do questions 18-20

Mathematics
1 answer:
Ipatiy [6.2K]3 years ago
6 0

Answer:


Step-by-step explanation:

18.-1139/500

19-21/20

20. 30/23

You might be interested in
Alice's average mark for 4 Science exams is 68%. Can Alice score enough marks in a fifth exam so that her average mark increases
Keith_Richards [23]

Answer:

It is not possible for Alice to score an average of 75% because what she needs to score in the fifth exam exceeds the maximum possible score.

Step-by-step explanation:

She scored an average 68% in all 4 exams.

This means; (68% + 68% + 68% + 68%)/4

Now, a fifth exam is added and we want to know if her average can now be 75%.

Thus, let the score in the 5th exam be x and we now have;

(68% + 68% + 68% + 68% + x)/5 = 75%

Multiply both sides by 5 to get;

(68% + 68% + 68% + 68% + x) = 375%

272% + x = 375%

x = 375% - 272%

x = 103%

The maximum score is 100% and therefore it is impossible for her to score 103%. Therefore it is not possible for Alice to score an average of 75%

7 0
3 years ago
Suppose you are going to conduct a two tail test concerning the population mean. Suppose that you do not know what the populatio
IRINA_888 [86]

Answer:

The critical value of <em>t</em> at 0.01 level of significance is 2.66.

Step-by-step explanation:

The hypothesis for the two-tailed population mean can be defined as:

<em>H₀</em>: <em>μ </em>= <em>μ₀</em> vs. <em>H₀</em>: <em>μ </em>≠ <em>μ₀</em>

It is provided that the population standard deviation is not known.

Since there is no information about the population standard deviation, we will use a <em>t</em>-test for single mean.

The test statistic is defined as follows:

t_{cal.}=\frac{\bar x-\mu}{s/\sqrt{n}}\sim t_{\alpha/2, (n-1)}

The information given is:

<em>n</em> = 55

<em>α</em> =<em> </em>0.01

Compute the critical value of <em>t</em> as follows:

t_{\alpha/2, (n-1)}= t_{0.01/2, (55-1)}=t_{0.005, 54}=2.66

*Use a <em>t</em>-table for the value.

If the desired degrees of freedom are not provided consider he next highest degree of freedom.

Thus, the critical value of <em>t</em> at 0.01 level of significance is 2.66.

4 0
3 years ago
Can someone help me please​
Andrej [43]

Answer: is A

Step-by-step explanation:

4 0
3 years ago
Read 2 more answers
3+2•[(2+1)•5+8]<br> Simplify the expression
Oksi-84 [34.3K]
*115*

do the parentheses in the parentheses first, then the outer parentheses, then the stuff outside the parentheses.


PEMDAS

parentheses...exponents...multiplication/division...Addition/subtraction.
3 0
3 years ago
2. Multiple Choice. Gary says, “I chose a number. I multiplied it by 5 and then
kkurt [141]

Answer:

The answer would be B

4 0
3 years ago
Read 2 more answers
Other questions:
  • An equilateral triangle has a length of 18 feet, determine the length of the triangle
    5·2 answers
  • Which of the following is the correct action to take when simplifying the expression (xy^2)^3
    11·1 answer
  • Identify the mistake.<br><br> What is the correct value for x? Type your answer in the answer box.
    8·1 answer
  • Find the volume of the hemisphere shown. remember a hemisphere is half of a sphere. r = 5
    5·1 answer
  • An animal shelter had 28 puppies. If the puppies are 28℅ of the total dog and cat population, how many dogs and cats are in the
    9·1 answer
  • Match the base to the corresponding height
    11·1 answer
  • The value of √1.2321<br>​
    14·2 answers
  • A rectangular sheet of paper is folded diagonally. What is the length of XY?
    12·1 answer
  • Which statement is true when 3.4 is placed in the blank? 10.2 ÷ ___ = 0.3 20.4 ÷ 6 = ___ 27.2 ÷ ___ = 0.8 30.6 ÷ 0.9 = ___
    8·2 answers
  • Sparky the Bear is atop a 100 foot tower. He is looking out over a fairly level area for careless people who might start fires.
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!