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astra-53 [7]
3 years ago
8

Customers at a gas station pay with a credit card (A), debit card (B), or cash (C). Assume that successive customers make indepe

ndent choices with P(A) = 0.6, P(B) = 0.3, and P(C) = 0.1.
(a) Among the next 100 customers, what are the mean and variance of the number who pay with a debit card?
Mathematics
1 answer:
Maurinko [17]3 years ago
7 0

Answer:

Mean = 20

Variance = 16

Step-by-step explanation:

Solution:-

- Let X be the number of customers paying with a debit card.  X has the binomial distribution with n = 100 trials and success probability p = 0.2  

- In general, if X has the binomial distribution with (n) trials and a success probability of (p) then:

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

                 for values of x = 0, 1, 2, ..., n  

                 P[X = x] = 0 for any other value of x.

- The probability mass function is derived by looking at the number of combination of x objects chosen from n objects and then a total of x success and n - x failures.  

- Or, in other words, the binomial is the sum of n independent and identically distributed Bernoulli trials.

                  X ~ Binomial( n = 100 , p = 0.2 )

- The mean of the binomial distribution is n * p = 20  

- The variance of the binomial distribution is n * p * (1 - p) = 16  

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Select the correct order for the following numbers
Andru [333]

Answer:

cdab

Step-by-step explanation:

3 0
3 years ago
Read 2 more answers
9. Carla has $200 in her bank account.
Firdavs [7]

(a) Linear Equation:   f(x) = 200 - 20x

(b) x-intercept : (10,0)

(c) y-intercept : (0,200)

(d) Domain : {0,1,2,3,4,5,6,7,8,9,10}

    Range : {0,1,2,...,200}

Step-by-step explanation:

Step 1: As we can see in graph, money in Carla is decreasing in multiples of 20 can be referred as 20x.

Every week $20 is getting deducted from the total amount of $200.

Step 2: (a) So we can quote it in equation as,

f(x) = 200 - 20x

where x represents number of weeks

Step 3: (b) x-intercept is where value of y becomes 0.

So, referring graph we can determine x intercept as x = 10. Point (10,0). which also means no money left in account.

Step 4: (c) y-intercept is where value of x becomes 0.

So, referring graph we can determine y intercept as y = 200. Point (0,200). which is starting value of money in account.

Step 5: (d) Domain : {0,1,2,3,4,5,6,7,8,9,10}

                  Range : {0,1,2,...,200}

4 0
3 years ago
Can anyone pls help me with this I'll mark as brainlist for correct answer please do explain in detail each answers Ty! (I'm pre
densk [106]

<u>Question 8</u>

a^2 + 7a + 12

= (a+3)(a+4)

When factorising a quadratic, the product of the two factors should equal the constant term (12), and the sum of the two factors should equal the linear term (7). To find the two factors, list out the factors of 12 (1x12, 2x6, 3x4) and identify the pair that adds up to 7 (3+4).

An alternative method if you get stuck during your exam would be to solve it algebraically using the quadratic formula and then write it in the factorised form.

a = (-7 +or- sqrt(7^2 - 4(1)(12)) / 2(1)

= (-7 +or- sqrt(1))/2

= -3 or -4

These factors are the negative of the values that would go in the brackets when written in factorised form, as when a = -3 the factor (a+3) would equal 0. (If it were positive 3 instead, then in the factorised form it would be a-3).

<u>Question 10</u>

-3(x - y)/9 + (4x - 7y)/2 - (x + y)/18

Rewrite each fraction with a common denominator so you can combine the fractions into one.

= -6(x - y)/18 + 9(4x - 7y)/18 - (x + y)/18

= (-6(x - y) + 9(4x - 7y) - (x + y)) /18

Expand the brackets and collect like terms.

= (-6x + 6y + 36x - 63y - x - y)/18

= (29x - 58y)/18

= 29/18 x - 29/9 y

7 0
2 years ago
Domain:<br> Range:<br> Increasing:<br> Decreasing:
mihalych1998 [28]

Answer:

Domain- -2>x<2

Range- [4,∞)

Increasing-[∞,4]

Decreasing-[4,∞]

3 0
3 years ago
10. Which equation could be used to solve the problem? Joan picked 4 bushels of apples in one hour. At that rate, how many bushe
Ratling [72]
The answer would be B. b = 8 * 4. If Joan picked 4 bushels of apples in an hour and the question wants to know how many bushels could be picked in 8 hours, its basically asking how many bushels are in 8 groups of 4.
4 0
3 years ago
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