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
ExtremeBDS [4]
3 years ago
9

A multiple choice test has four possible answers for each question. Let X be the number of correct responses in a test of 100 qu

estions if the student simply guesses on each question. The standard deviation of X is
a. 4.33.
b. 18.75.
c. 0.433.
Mathematics
1 answer:
dimulka [17.4K]3 years ago
7 0

Answer:

a. 4.33.

Step-by-step explanation:

If there is only one correct answer out of four alternatives, the expected proportion of correct answers is p =0.25

Sample size (n) = 100 questions

The standard deviation of a proportion 'p' is given by:

s=\sqrt{\frac{p*(1-p)}{n} }

Applying the given data:

s=\sqrt{\frac{0.25*(1-0.25)}{100}}\\s=0.0433

If X is the number of correct responses in 100 guesses, the standard deviation of X is:

\sigma = n*s=100*0.0433\\\sigma = 4.33

The standard deviation of X is 4.33 questions.

You might be interested in
What’s the answer for this?
fgiga [73]

Answer:

1.98

Step-by-step explanation:

Use SOH-CAH-TOA:

Sine = Opposite / Hypotenuse

Cosine = Adjacent / Hypotenuse

Tangent = Opposite / Adjacent

Here, we're given the hypotenuse is 4.5, and we want to find the side opposite of the 26° angle.  So we should use sine.

sin 26° = x / 4.5

0.44 = x / 4.5

x = 1.98

7 0
3 years ago
8. Five times a number minus 4 is six.​
Semmy [17]

Answer:

2

Step-by-step explanation:

Let n equal that number.

5n-4=6

5n=10

n=2

7 0
3 years ago
Read 2 more answers
Solve for X using either sine, cosine, or tangent
vovikov84 [41]

Answer:

•12.12

•56.92

Step-by-step explanation:

•Sin 30° = x ÷ 14√3

x=14√3 *Sin30

x=7√3

x=12.12

•Tan30°=6√3÷x

x=6√30 ÷Tan 30

x=18√10

x=56.92

7 0
3 years ago
PLZ HELP!!! TIMED WORKSHEET
bogdanovich [222]

Answer:1.   152.4

2.    0.0009

3.    680

Step-by-step explanation:

7 0
3 years ago
Someone plz explain!
ryzh [129]

Answer:

18° and 72°

Step-by-step explanation:

Complimentary angles form 90°

We have an angle (x) 4 times larger than the other (y).

Well actually, a system of equations isn't required, so forget about x and y, just divide 90 by 5. This gives you 18, one of the angle's measurements is 18°. Multiply 18 by 4 and get 72. The other angle's measurement is 72°.

7 0
3 years ago
Other questions:
  • A foam toy is 2 inches wide. It doubles in size for every minute it is in water. Write an expression for the width of the toy af
    8·1 answer
  • How do I solve for x<br><img src="https://tex.z-dn.net/?f=%20-%204x%20-%206%20%2B%202x%20%3D%20%20-%2014x" id="TexFormula1" titl
    10·1 answer
  • Which values for a b will create infinitely many solutions?
    6·1 answer
  • The sign for a new restaurant will be a triangle with a base of 8 feet and a height of 3 feet. The painter needs to know if he h
    13·1 answer
  • Identify the method that will be used to solve for x for each equation.<br> 4x = 20
    13·1 answer
  • Dylan is evaluating the expression 13+19+7+10. At one step in his work, Dylan rewrites the equation as 13+7+19+10. Which propert
    8·2 answers
  • the graph of a circle that represents a large pool to be built at a hotel.the circle has center (-90, -60) and radius 75 ft. wha
    8·1 answer
  • Greg wants to buy four pieces of candy. They cost $1.37, $0.69, $0.89, and $1.15.
    6·2 answers
  • Write the Standard Form of the line with x-intercept of 3 and y-intercept of 4.
    11·1 answer
  • What answers is. I don’t know
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!