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3 years ago

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Mathematics

1 answer:

KatRina [158]3 years ago

5 0

Answer:

n = 60.22

Step-by-step explanation:

Hello

To find Sn, we need to draw out equations for each a₇ and a₁₉

In an arithmetic progression,

Sn = a + (n-1)d

Where Sn = sum of the A.P

a = first term

d = common difference

a₇ = 32

32 = a + (7-1)d

32 = a + 6d ........equation (i)

a₁₉ = 140

140 = a + (19-1)d

140 = a + 18d .........equation (ii)

Solve equation (i) and (ii) simultaneously

From equation (i)

32 = a + 6d

Make a the subject of formula

a = 32 - 6d .....equation (iii)

Put equation (iii) into equation (ii)

140 = (32 - 6d) + 18d

140 = 32 - 6d + 18d

Collect like terms

140 - 32 = 12d

12d = 108

d = 108 / 12

d = 9

Put d = 9 in equation (i)

32 = a + 6(9)

32 = a + 54

a = 32 - 54

a = -22

When Sn = 511

Sn = a + (n - 1)d

Substitute and solve for n

511 = -22 + (n-1) × 9

511 = -22 + 9n - 9

511 = -31 + 9n

511 + 31 = 9n

542 = 9n

n = 542 / 9

n = 60.22

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Answer:

h(x - 1) = -5x - 2

General Formulas and Concepts:

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Step-by-step explanation:

Step 1: Define

Identify

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Step 2: Find

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3 years ago

The volume of a gift box is 972 in. The height of the gift box is 12 inches

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Answer:

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3 years ago

What is the square root of 9?

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2 years ago

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Lisa Purchased almonds for $3.50 per pound. She spent a total of $24.50. how many pounds of almond did she purchase?

Margaret [11]

Answer:

7 pounds of almond

Step-by-step explanation:

It is $3.50 per pound.

If she spent a total of $24.50, just divide 24.50 by 3.50

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2 years ago

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Thirty percent of all customers who enter a department store will make a purchase. Suppose that 6 customers enter the store and

torisob [31]

Answer:

Step-by-step explanation:

Let's use binomial distribution, because we are interested in find the total number of successes in a sequence of n independent experiments.

In probability, a binomial distribution is used in a Bernoulli process. That is, a sequence of experiments of n independent trials, each asking a dichotomous question, that means it only has two answers. One answer is a success (probability: p) and the other is a failure (probability: 1-p). In this case, every customer who enters in the store is the experiment. If they make a purchase is a success event, taking into account that every purchase decision has to be independent.

$P(X=x) = C(n,x)p^{x} (1-p)^{n-x}$

x= total number of success

n= total number of experiments

p=probability of success on an indivual trial

$C(n,x) = \frac{n!}{x!(n-x)!}$

a) x= 5 ------> customers that make a purchase

n= 6 ------> total customers

p=0.3

$p(X=5)= C(6,5)(0.3)^{5} (1-0.3)^{6-5} \\p(X=5)=0.102$

b) At least 3 customers make a purchase. x ≥ 3

$P(X\geq 3)=1-P (X=0)-P(X=1)-P(X=2)\\P(X\geq 3)=1-(C(6,0)(0.3^{0})(0.7)^{6}) - (C(6,1)(0.3^{1})(0.7)^{5}) - (C(6,2)(0.3^{2})(0.7)^{4})\\ P(X\geq 3) = 1-0.11765-0.30253-0.32414\\P(X\geq3)= 0.2557$

c) At most 2 customers make a purchase. x ≤ 2

$P(X\leq2) = P(X=0) + P(X=1) + P(X=2)\\P(X\leq2) = (C(6,0)(0.3^{0})(0.7)^{6}) + (C(6,1)(0.3^{1})(0.7)^{5}) + (C(6,2)(0.3^{2})(0.7)^{4})\\P(X\leq2) = 0.11765-0.30253-0.32414\\P(X\leq2)=0.7443$

d)At least 1 customer makes a purchase. x ≥ 1

$P(X\geq 1)=1-P(X=0)\\P(X\geq 1)= 1-C(0,6)(0.3)^{0}(0.7)^{6} \\P(X\geq 1)= 1-0.11765 = 0.8824$

e)They must be kind to customers, always willing to help and give information about products clearly and honestly.

Have enough inventory and offer promotions for the purchase of more than one product

Have an agile payment system that avoids rows and delays in purchases.

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