Tommy has 5 jars of marbles. Each jar is 2/3 filled with marbles. How many jars of marbles does Tommy have

A hospital finds that 22% of its accounts are at least 1 month in arrears. A random sample of 425 accounts was taken. What is th

GenaCL600 [577]

Answer:

8.85% probability that fewer than 82 accounts in the sample were at least 1 month in arrears

Step-by-step explanation:

For each account, there are only two possible outcomes. Either they are at least 1 month in arrears, or they are not. The probability of an account being at least 1 month in arrears is independent from other accounts. So the binomial probability distribution is used to solve this question.

However, we are working with a large sample. So i am going to aproximate this binomial distribution to the normal.

Binomial probability distribution

Probability of exactly x sucesses on n repeated trials, with p probability.

Can be approximated to a normal distribution, using the expected value and the standard deviation.

The expected value of the binomial distribution is:

$E(X) = np$

The standard deviation of the binomial distribution is:

$\sqrt{V(X)} = \sqrt{np(1-p)}$

Normal probability distribution

Problems of normally distributed samples can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

When we are approximating a binomial distribution to a normal one, we have that $\mu = E(X)$ , $\sigma = \sqrt{V(X)}$ .

In this problem, we have that:

$p = 0.22, n = 425$

So

$\mu = E(X) = np = 425*0.22 = 93.5$

$\sigma = \sqrt{V(X)} = \sqrt{np(1-p)} = \sqrt{425*0.22*0.78} = 8.54$

What is the probability that fewer than 82 accounts in the sample were at least 1 month in arrears

This probability is the pvalue of Z when X = 82. So

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{82 - 93.5}{8.54}$

$Z = -1.35$

$Z = -1.35$ has a pvalue of 0.0885.

8.85% probability that fewer than 82 accounts in the sample were at least 1 month in arrears

8 0

1 year ago

To better understand how husbands and wives feel about their finances, Money Magazine conducted a national poll of 1010 married

Xelga [282]

Answer:

a. See the table below

b. See the table below

c. 0.548

d. 0.576

e. 0.534

f) i) 0.201, ii) 0.208

Explanation:

First, order the information provided:

Table: "Who is better at getting deals?"

Who Is Better?

Respondent I Am My Spouse We Are Equal

Husband 278 127 102

Wife 290 111 102

a. Develop a joint probability table and use it to answer the following questions. 

The joint probability table shows the same information but as proportions. Hence, you must divide each number of the table by the total number of people in the set of responses.

1. Number of responses: 278 + 127 + 102 + 290 + 111 + 102 = 1,010.

2. Calculate each proportion:

278/1,010 = 0.275
127/1,010 = 0.126
102/1,010 = 0.101
290/1,010 = 0.287
111/1,010 = 0.110
102/1,010 = 0.101

3. Construct the table with those numbers:

Joint probability table:

Respondent I Am My Spouse We Are Equal

Husband 0.275 0.126 0.101

Wife 0.287 0.110 0.101

Look what that table means: it tells that the joint probability of being a husband and responding "I am" is 0.275. And so for every cell: every cell shows the joint probability of a particular gender with a particular response.

Hence, that is why that is the joint probability table.

b. Construct the marginal probabilities for Who Is Better (I Am, My Spouse, We Are Equal). Comment.

The marginal probabilities are calculated for each for each row and each column of the table. They are shown at the margins, that is why they are called marginal probabilities.

For the colum "I am" it is: 0.275 + 0.287 = 0.562

Do the same for the other two colums.

For the row "Husband" it is 0.275 + 0.126 + 0.101 = 0.502. Do the same for the row "Wife".

Table Marginal probabilities:

Respondent I Am My Spouse We Are Equal Total

Husband 0.275 0.126 0.101 0.502

Wife 0.287 0.110 0.101 0.498

Total 0.562 0.236 0.202 1.000

Note that when you add the marginal probabilities of the each total, either for the colums or for the rows, you get 1. Which is always true for the marginal probabilities.

c. Given that the respondent is a husband, what is the probability that he feels he is better at getting deals than his wife? 

For this you use conditional probability.

You want to determine the probability of the response be " I am" given that the respondent is a "Husband".

Using conditional probability:

P ( "I am" / "Husband") = P ("I am" ∩ "Husband) / P("Husband")

P ("I am" ∩ "Husband) = 0.275 (from the intersection of the column "I am" and the row "Husband)

P("Husband") = 0.502 (from the total of the row "Husband")

P ("I am" ∩ "Husband) / P("Husband") = 0.275 / 0.502 = 0.548

d. Given that the respondent is a wife, what is the probability that she feels she is better at getting deals than her husband?

You want to determine the probability of the response being "I am" given that the respondent is a "Wife", for which you use again the formula for conditional probability:

P ("I am" / "Wife") = P ("I am" ∩ "Wife") / P ("Wife")

P ("I am" / "Wife") = 0.287 / 0.498

P ("I am" / "Wife") = 0.576

e. Given a response "My spouse," is better at getting deals, what is the probability that the response came from a husband?

You want to determine: P ("Husband" / "My spouse")

Using the formula of conditional probability:

P("Husband" / "My spouse") = P("Husband" ∩ "My spouse")/P("My spouse")

P("Husband" / "My spouse") = 0.126/0.236

P("Husband" / "My spouse") = 0.534

f. Given a response "We are equal" what is the probability that the response came from a husband? What is the probability that the response came from a wife?

What is the probability that the response came from a husband?

P("Husband" / "We are equal") = P("Husband" ∩ "We are equal" / P ("We are equal")

P("Husband" / "We are equal") = 0.101 / 0.502 = 0.201

What is the probability that the response came from a wife:

P("Wife") / "We are equal") = P("Wife" ∩ "We are equal") / P("We are equal")

P("Wife") / "We are equal") = 0.101 / 0.498 = 0.208

6 0

2 years ago

Pq=6x+25 and qr=16-3x; find pr

Viktor [21]

$Given:\\\overline{PQ}=6x+25\\\overline{QR}=16-3x\\\\Finding:\overline{PR}$

$If \; Q \; is \; a \; point \; in \; between \; the \; line \; segment \; \overline{PR}, \; \\ then \; the \; distance \; of \; line \; segment \; \overline{PR} \; \\ can \; be \; found \; by \; adding \; line \; segment \; \overline{PQ} \; and \; \overline{QR}.$

$Using \; the \; concept \; \overline{PQ}+\overline{QR}=\overline{PR} \;,\\ we \; need \; to \; set \; up \; an \; equation \; given \; below:$

$\overline{PR} =6x+25 +16-3x\\\\Step \; 1: Grouping \; Like \; Terms\\\overline{PR} =6x-3x+25 +16\\\\Step \; 2: Combining \; Like \; Terms\\\overline{PR} =3x+41$

Conclusion:

$\overline{PR} \; is \; represented \; the \; expression \; 3x +41$

3 0

1 year ago

Read 2 more answers

Triangular numbers can be represented with equilateral triangles formed by dots. The first five triangular numbers are 1, 3, 6,

Alisiya [41]

Direct variation is y = kx where y would be the value of the number and x would be its position in the sequence, k is a constant

so for consecutive values y/x would be a constant k
In this case its not true becuse for example 3/1 = 3 and 6/3 = 2

so there is no direct variation here.

7 0

2 years ago

Read 2 more answers

Without plotting any points other than intercepts, draw a possible graph of the following polynomial:

babunello [35]

The first thing to do is find the x-intercepts of the function so that you can plot them. Set the function f(x) to zero and find the values of x.

0 = (x + 8)3(x + 6)2(x + 2)(x − 1)3(x − 3)4(x − 6)
There are 6 intercepts:
x+8=0 ---> x= -8
x+6=0 ---> x=-6
x+2=0 ---> x=-2
x-1=0 ---> x=1
x-3=0 ---> x=3
x-6=0 ---> x=6

The 6 intercepts are plotted as shown in the picture. The tool I used was Microsoft Excel. This is one possible sketch of the graph. The trend could move in any ways as long as it passes these 6 intercepts.

4 0

1 year ago

Read 2 more answers