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
vaieri [72.5K]
3 years ago
13

Ratiooo answer and working out pleaseee!! 18 points

Mathematics
1 answer:
miskamm [114]3 years ago
3 0

Answer: 96 green pens sold

Step-by-step explanation:

Black = 3 pens

Red = 5 pens

Green = 6 pens

--

Black = 7 packs

Red = 2 packs

Green = 4 packs

--

Black = 3 x 7 = 21 total pens

Red = 5 x 2 = 10 total pens

Green = 6 x 4 = 24 total pens

Total units for total pens = 21 + 10 + 24 = 55u

55u = 220

1u = 220/55

    = 4

24u = 4 x 24

       = 96 green pens sold

--

96 green pens were sold.

You might be interested in
Let $$X_1, X_2, ...X_n$$ be uniformly distributed on the interval 0 to a. Recall that the maximum likelihood estimator of a is $
Solnce55 [7]

Answer:

a) \hat a = max(X_i)  

For this case the value for \hat a is always smaller than the value of a, assuming X_i \sim Unif[0,a] So then for this case it cannot be unbiased because an unbiased estimator satisfy this property:

E(a) - a= 0 and that's not our case.

b) E(\hat a) - a= \frac{na}{n+1} - a = \frac{na -an -a}{n+1}= \frac{-a}{n+1}

Since is a negative value we can conclude that underestimate the real value a.

\lim_{ n \to\infty} -\frac{1}{n+1}= 0

c) P(Y \leq y) = P(max(X_i) \leq y) = P(X_1 \leq y, X_2 \leq y, ..., X_n\leq y)

And assuming independence we have this:

P(Y \leq y) = P(X_1 \leq y) P(X_2 \leq y) .... P(X_n \leq y) = [P(X_1 \leq y)]^n = (\frac{y}{a})^n

f_Y (Y) = n (\frac{y}{a})^{n-1} * \frac{1}{a}= \frac{n}{a^n} y^{n-1} , y \in [0,a]

e) On this case we see that the estimator \hat a_1 is better than \hat a_2 and the reason why is because:

V(\hat a_1) > V(\hat a_2)

\frac{a^2}{3n}> \frac{a^2}{n(n+2)}

n(n+2) = n^2 + 2n > n +2n = 3n and that's satisfied for n>1.

Step-by-step explanation:

Part a

For this case we are assuming X_1, X_2 , ..., X_n \sim U(0,a)

And we are are ssuming the following estimator:

\hat a = max(X_i)  

For this case the value for \hat a is always smaller than the value of a, assuming X_i \sim Unif[0,a] So then for this case it cannot be unbiased because an unbiased estimator satisfy this property:

E(a) - a= 0 and that's not our case.

Part b

For this case we assume that the estimator is given by:

E(\hat a) = \frac{na}{n+1}

And using the definition of bias we have this:

E(\hat a) - a= \frac{na}{n+1} - a = \frac{na -an -a}{n+1}= \frac{-a}{n+1}

Since is a negative value we can conclude that underestimate the real value a.

And when we take the limit when n tend to infinity we got that the bias tend to 0.

\lim_{ n \to\infty} -\frac{1}{n+1}= 0

Part c

For this case we the followng random variable Y = max (X_i) and we can find the cumulative distribution function like this:

P(Y \leq y) = P(max(X_i) \leq y) = P(X_1 \leq y, X_2 \leq y, ..., X_n\leq y)

And assuming independence we have this:

P(Y \leq y) = P(X_1 \leq y) P(X_2 \leq y) .... P(X_n \leq y) = [P(X_1 \leq y)]^n = (\frac{y}{a})^n

Since all the random variables have the same distribution.  

Now we can find the density function derivating the distribution function like this:

f_Y (Y) = n (\frac{y}{a})^{n-1} * \frac{1}{a}= \frac{n}{a^n} y^{n-1} , y \in [0,a]

Now we can find the expected value for the random variable Y and we got this:

E(Y) = \int_{0}^a \frac{n}{a^n} y^n dy = \frac{n}{a^n} \frac{a^{n+1}}{n+1}= \frac{an}{n+1}

And the bias is given by:

E(Y)-a=\frac{an}{n+1} -a=\frac{an-an-a}{n+1}= -\frac{a}{n+1}

And again since the bias is not 0 we have a biased estimator.

Part e

For this case we have two estimators with the following variances:

V(\hat a_1) = \frac{a^2}{3n}

V(\hat a_2) = \frac{a^2}{n(n+2)}

On this case we see that the estimator \hat a_1 is better than \hat a_2 and the reason why is because:

V(\hat a_1) > V(\hat a_2)

\frac{a^2}{3n}> \frac{a^2}{n(n+2)}

n(n+2) = n^2 + 2n > n +2n = 3n and that's satisfied for n>1.

8 0
3 years ago
Jackson started writing a story at 8:30 AM He stopped writing at 1:15 P.M. How long did he write?​
Scilla [17]

Answer: he wrote for an five hours and forty-five minutes

Step-by-step explanation:

7 0
3 years ago
(picture)<br>circle the numbers that are divisble by the number given ​
Dmitry [639]

Answer:

Hope that this helps!!!

3 0
3 years ago
Help I will mark brainliestttt
Tresset [83]

Answer:

c

Step-by-step explanation:

its c

8 0
2 years ago
40 POINTS!
lukranit [14]

Answer:

B.76 square feet

Step-by-step explanation:

SA=B+L

6 0
2 years ago
Read 2 more answers
Other questions:
  • Part I: Marco rented a small moving van. The moving company charges $40 a day for up to 5 days. The input is the time, in days,
    11·1 answer
  • Draw a model for a fraction1/6
    13·2 answers
  • Determine if <img src="https://tex.z-dn.net/?f=m%5E%7B2%7D%20" id="TexFormula1" title="m^{2} " alt="m^{2} " align="absmiddle" cl
    15·1 answer
  • Sixty three thousandths in standard form
    15·1 answer
  • 16 rolls of toilet paper come in a pack. What is the cost per roll if the
    6·2 answers
  • Which of the following is a true proportion
    8·2 answers
  • Coordinate plane with triangle EFG with E at 0 comma 5, F at 1 comma 1, and G at negative 2 comma 1. Point H at 1 comma 1 is on
    9·2 answers
  • Plzzzz helllp mmmmeee thx
    15·2 answers
  • PLEASE HELP THIS IS DUE IN THIRTY MINUTES
    6·1 answer
  • A pack of cinnamon scented pencils sell for $4.00 what is the sales tax rate if the total cost of the pencils is $4.32
    14·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!