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
Ilia_Sergeevich [38]
2 years ago
15

A box contains four 75 W lightbulbs, three 60 W lightbulbs, and three burned-out lightbulbs. Two bulbs are selected at random fr

om the box without replacement. Let X represent the number of 75 W bulbs selected. Find the probability mass function for X. Show that X follows a valid probability mass function.
a. Find P( X > 0)
b. Find μx
c. Find σx^2
Mathematics
1 answer:
Law Incorporation [45]2 years ago
6 0

Answer:

a. 0.689

b. 0.8

c. 0.427

Step-by-step explanation:

The given scenario indicates hyper-geometric experiment because because successive trials are dependent and probability of success changes on each trial.

The probability mass function for hyper-geometric distribution is

P(X=x)=kCx(N-k)C(n-x)/NCn

where N=4+3+3=10

n=2

k=4

a.

P(X>0)=1-P(X=0)

The probability mass function for hyper-geometric distribution is

P(X=x)=kCx(N-k)C(n-x)/NCn

P(X=0)=4C0(6C2)/10C2=15/45=0.311

P(X>0)=1-P(X=0)=1-0.311=0.689

P(X>0)=0.689

b.

The mean of hyper-geometric distribution is

μx=nk/N

μx=2*4/10=8/10=0.8

c.

The variance of hyper-geometric distribution is

σx²=nk(N-k).(N-n)/N²(N-1)

σx²=2*4(10-4).(10-2)/10²*9

σx²=8*6*8/900=384/900=0.427

You might be interested in
I need help! with numbers 13-16!!!!
Nina [5.8K]
Well, I'm not going to give you the answers, but first erase the "(variable) =". They already gave you the value of the variables, so you just have to multiply the variables, like for example, "7/8 × c, c = 6". It's telling you to multiply 7/8 by 6. The rest goes for everything and in the future, instead of writing it as 7/8 × c, it'll say 7/8c.

So yeah, just multiply the number by the variable, which already has a given value.

Put as brainliest =D
8 0
3 years ago
Read 2 more answers
A house has increased in value by 38% since it was purchased. If the current value is $621,000 what was the value when it was pu
olganol [36]

Answer:

38%

Step-by-step explanation:

6 0
3 years ago
Examples: Determine if the graph is a function. If it is, state the domain and range.
NemiM [27]

Answer:

Another way to identify the domain and range of functions is by using graphs. Because the domain refers to the set of possible input values, the domain of a graph consists of all the input values shown on the x-axis. The range is the set of possible output values, which are shown on the y-axis.Jan 8, 2019

Step-by-step explanation:

5 0
3 years ago
Alyssa said that 6/8 and 9/12 are not equivalent because there's no whole number you can multiply both parts of 6/8 by to get 9/
luda_lava [24]
No. 6/8=9/12
by multiplying the denominators you get the common denominator of 72
then multiply each numerator by the number of the opposite denominator
8x12=96
6x12=72
9x8=72
Therefore, 72/96=72/96
                   (6/8   = 9/12)
5 0
3 years ago
Read 2 more answers
The zeroes of the polynomial f(x) = x^2+x+3/4 are​
matrenka [14]

Step-by-step explanation:

f(x) = x² + x + 3/4

in general, such a quadratic function is defined as

f(x) = a×x² + b×x + c

the solution for finding the values of x where a quadratic function value is 0 (there are as many solutions as the highest exponent of x, so 2 here in our case)

x = (-b ± sqrt(b² - 4ac))/(2a)

in our case

a = 1

b = 1

c = 3/4

x = (-1 ± sqrt(1² - 4×1×3/4))/(2×1) =

= (-1 ± sqrt(1 - 3))/2 = (-1 ± sqrt(-2))/2 =

= (-1 ± sqrt(2)i)/2

x1 = (-1 + sqrt(2)i) / 2

x2 = (-1 - sqrt(2)i) / 2

remember, i = sqrt(-1)

f(x) has no 0 results for x = real numbers.

for the solution we need to use imaginary numbers.

6 0
2 years ago
Read 2 more answers
Other questions:
  • Nine times the sum of a number and two is forty five. What is the number? {Write an equation.}
    12·1 answer
  • The green line below____. Check all that apply. I need help plz
    10·1 answer
  • For several months, a restaurant manager collected data on the number of people at a table (p) and the total bill, in dollars (d
    12·2 answers
  • Sandy has $200 in her bank account. If she writes 6 checks for exactly $19.98, what expression describes the change in her bank
    13·1 answer
  • It takes Jill 2 hours to run 14.5 miles. At this rate, how far could she run in 3 hours?
    5·2 answers
  • Slove all of it please 100 points
    11·2 answers
  • What is 20 x 3/4 in simplest form?
    14·2 answers
  • A tree is 52 inches tall. How tall is it in feet and inches?
    15·2 answers
  • the track has to meet certain specfications the largest angle, angle c is triple the smallest angle, angle B. Angle, A is double
    13·1 answer
  • Help me find the radius please. ​
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!