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
ss7ja [257]
3 years ago
10

A multiple-choice standard test contains total of 25 questions, each with four answers. Assume that a student just guesses on ea

ch question and all questions are answered independently. (a) What is the probability that the student answers more than 20 questions correctly? (b) What is the probability that the student answers fewer than 5 questions correctly?
Mathematics
1 answer:
weqwewe [10]3 years ago
7 0

Answer:

a)  8*88*10⁻⁶ ( 0.00088 %)

b) 0.2137 (21.37%)

Step-by-step explanation:

if the test contains 25 questions and each questions is independent of the others, then the random variable X= answer "x" questions correctly , has a binomial probability distribution. Then

P(X=x)= n!/((n-x)!*x!)*p^x*(1-p)^(n-x)

where

n= total number of questions= 25

p= probability of getting a question right = 1/4

then

a) P(x=n) = p^n = (1/4)²⁵ = 8*88*10⁻⁶ ( 0.00088 %)

b) P(x<5)= F(5)

where F(x) is the cumulative binomial probability distribution- Then from tables

P(x<5)= F(5)= 0.2137 (21.37%)

You might be interested in
A movie theater charges $9.50 for adults and $4.50 for children. For a recent showing of a movie, the theater sold 33 tickets an
choli [55]

Answer:

The  number of children's tickets sold was 31 and the number of  adult tickets sold was 2

Step-by-step explanation:

Let

x ---> the number of children's tickets sold

y ---> the number of  adult tickets sold

we know that

the theater sold 33 tickets

so

x+y=33 -----> equation A

the theater made a total of $158.50

so

4.50x+9.50y=158.50 ----> equation B

Solve the system by graphing

Remember that the solution of the system is the intersection point both graphs

using a graphing tool

The solution is the point (31,2)

see the attached figure

therefore

The  number of children's tickets sold was 31 and the number of  adult tickets sold was 2

5 0
3 years ago
Helpppppppp pweaseeeee
AlladinOne [14]

length=6

breath=15

height=12

therefore,12+3+15

=30cm

6 0
3 years ago
Read 2 more answers
Steel loading ramps are used to load a
tia_tia [17]

Answer:

6.25 feet.

Step-by-step explanation:

Let L be the length of the ramp in feet.  

We have been given that steel loading ramps are used to load a lawn mower onto a truck bed 37.5 inches above the ground. The ramp make a 30° angle with the ground.

We can see from our attachment that ramp and truck bed forms a right triangle with ground. The truck bed is opposite side and length of ramp is hypotenuse of our given angle.

Since we know that Sine relates the opposite and hypotenuse of a right triangle, so we will use Sine to solve for L.

Upon substituting our given values in above formula we will get,

Therefore, the length of the ramp is 75 inches.

Let us convert the length of ramp in feet.

1 feet = 12 inches.

Therefore, the length of the ramp is 6.25 feet.

6 0
3 years ago
F(x)=x2+3x-5 and g(x)=x/4-6.g(x)=x/4-6
xenn [34]

Answer:

idk the answer but i use socratic by google to take pictures of the problems and find answers online, and also cymath.com is a really great place to get answers for math, i hope this helps!

Step-by-step explanation:

5 0
3 years ago
Read 2 more answers
What is the mixed number for 200 35/7
Mama L [17]

\text{Hey there!}

\text{What is the mixed number for 200}\dfrac{35}{7}\ ?\\\\\bf{200\dfrac{35}{7}=200\times7= 1400;\ \ 1400 + 35 = 1435}\\\\\text{Your new fraction becomese:}\dfrac{1435}{7}\\\\\bf{\dfrac{1435\div7=205}{7\div7=1}=\dfrac{205}{1}= 205}\\\\\\\\\boxed{\boxed{\bf{Answer: \dfrac{1435}{7} \ or \ \ 205}}}\checkmark

\text{Good luck on your assignment and enjoy your day!}\\\\\\\frak{LoveYourselfFirst:)}

7 0
3 years ago
Other questions:
  • (04.04)marisa painted one-half of her bedroom in three-fourths of an hour. at this rate, how long would it take her the paint th
    10·2 answers
  • “which expression is the factored form of x^2-7x+10?”
    15·1 answer
  • How to write 32,005,008 in expanded form?
    11·1 answer
  • Can you also please explain, I need this done very fast
    12·1 answer
  • Basma cuts ribbon to its onto balloons for the carnival. She has 925.6 inches of ribbon in all. If each ribbon must be 24 inches
    7·1 answer
  • Nina goes to the supermarket 0, 1, or 2 times in a week. The probability that she goes 0 days is 0.2, the probability that she g
    14·1 answer
  • What is the slope of the line through the points (–3, 5) and (4, 5)? undefined 0 2 –2
    13·2 answers
  • Evaluate the function f(x) = 2x3 - 6x + 1 for f(-2).
    12·1 answer
  • An airplane is flying with a constant altitude at a speed of 450 mph in a direction 10° north of west directly towards its final
    8·1 answer
  • You set a goal of creating a $16,000 emergency fund. You earn a salary of $40,000 per year
    14·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!