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2 years ago

The average of a set of 18 consecutive integers is 22.5. what is the smallest integer in the set?

1 answer:

6 0

The sum of the 18 numbers is 22.5 x 18 = 405.
Let the numbers be x, x + 1, x + 2, . . ., x + 17

Sum of n term of an arithmetic sequence = n/2(a + l)
18/2(x + x + 17) = 405
9(2x + 17) = 405
2x + 17 = 405/9 = 45
2x = 45 - 17 = 28
x = 28/2 = 14

Therefore, the smallest integer is 14.

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Tamara was asked to write an example of a linear functional relationship. She wrote this example: My babysitting service charges

Vlada [557]

Answer:

Hours Charge

1 y = 6.5(1) + 5 = $11.5

2 y = 6.5(2) + 5 = $18

3 y = 6.5(3) + 5 = $24.5

4 y = 6.5(4) + 5 = $31

Step-by-step explanation:

In an equation y=mx+b, we can interpret the intercept b as the value of the initial charge and the slope m as the additional charge per hour. So, we can formulate the following equation:

y = 6.5x + 5

Where x is the hours and y are the charges for the babysitting, so, we can fill the table as:

Hours Charge

1 y = 6.5(1) + 5 = $11.5

2 y = 6.5(2) + 5 = $18

3 y = 6.5(3) + 5 = $24.5

4 y = 6.5(4) + 5 = $31

7 0

1 year ago

A land surveyor places two stakes 500 ft apart and creates a perpendicular to the line that connects these two stakes. He needs

cupoosta [38]

Answer:
We will choose the last option is correct.
Step-by-step explanation:
A land surveyor places two stakes 500 ft apart and locates the midpoint between the stakes.
From the midpoint, he needs to place another stake 100 ft away that is equidistant to the two original stakes.
Therefore, to apply the Perpendicular Bisector Theorem, the land surveyor would have to identify a line that is "perpendicular to the line connecting the two stakes and going through the midpoint of the two stakes".
Therefore we will choose the last option is correct. (Answer)

8 0

2 years ago

Read 2 more answers

What is a31 of the arithmetic sequence for which a5=12.4 and a9=22.4

miv72 [106K]

For the arithmetic sequence
a₁, a₂, a₃, ...,
the n-th term is
$a_{n}=a_{1}+(n-1)d$
where d = the common difference

Because a₅ = 12.4,
a₁ + 4d = 12.4 (1)
Because a₉ = 22.4,
a₁ + 8d = 22.4 (2)

Subtract (1) from (2).
a₁ + 8d - (a₁ + 4d) = 22.4 - 12.4
4d = 10
d = 2.5
From (1),
a₁ = 12.4 - 4*2.5 = 2.4

Therefore
a₃₁ = 2.4 + 30*2.5 = 77.4

Answer: a₃₁ = 77.4

6 0

2 years ago

3. Blackberry is also in the business of selling phones. The data for the profit that Blackberry makes on selling tablets is rep

vesna_86 [32]

Here is my answer. I left the latter question in a. as I don't actually know the answer. Anyway, I hope this is helpful although not complete.

8 0

1 year ago

Customers are used to evaluate a preliminary product design. In the past, 95% of highly successful products received good review

Sever21 [200]

Answer:

a. 61.5%; b. About 61.8%; c. About 36.4%

Step-by-step explanation:

This is a kind of question that we can solve using the Bayes' Theorem. We have here all the different conditional probabilities we need to solve this problem.

According to that theorem, the probability of a selected product attains a good review is:

$\\ P(G) = P(G|H)*P(H) + P(G|M)*P(M) + P(G|P)*P(P)$ (1)

In words, the probability that a selected product attains a <em>good review</em> is an <em>event </em>that depends upon the sum of the conditional probabilities that the product comes from <em>high successful product</em> P(G|H) by the probability that this product is a <em>highly successful product</em> P(H), plus the same about the rest of the probabilities, that is, P(G|M)*P(M) or the probability that the product has a good review coming from a <em>moderately successful</em> product by the probability of being moderately successful, and a good review coming from a poor successful product by the probability of being poor successful or P(G|P)*P(P).

<h3>The probability that a randomly selected product attains a good review</h3>

In this way, the probability that a randomly selected product attains a good review is the result of the formula (1). Where (from the question):

P(G|H) = 95% or 0.95 (probability of receiving a good review being a highly successful product)

P(G|M) = 60% or 0.60 (probability of receiving a good review being a moderately successful product)

P(G|P) = 10% or 0.10 (probability of receiving a good review being a poorly successful product)

P(H) = 40% or 0.40 (probability of being a highly successful product).

P(M) = 35% or 0.35 (probability of being a moderately successful product).

P(P) = 25% or 0.25 (probability of being a poor successful product).

Then,

$\\ P(G) = P(G|H)*P(H) + P(G|M)*P(M) + P(G|P)*P(P)$

$\\ P(G) = 0.95*0.40 + 0.60*0.35 + 0.10*0.25$

$\\ P(G) = 0.615\;or\; 61.5\%$

That is, <em>the probability that a randomly selected product attains a good review</em> is 61.5%.

<h3>The probability that a new product attains a good review is a highly successful product</h3>

We are looking here for P(H|G). We can express this probability mathematically as follows (another conditional probability):

$\\ P(H|G) = \frac{P(G|H)*P(H)}{P(G)}$

We can notice that the probability represents a fraction from the probability P(G) already calculated. Then,

$\\ P(H|G) = \frac{0.95*0.40}{0.615}$

$\\ P(H|G) =\frac{0.38}{0.615}$

$\\ P(H|G) =0.618$

Then, the probability of a product that attains a good review is indeed a highly successful product is about 0.618 or 61.8%.

<h3>The probability that a product that <em>does not attain </em>a good review is a moderately successful product</h3>

The probability that a product does not attain a good review is given by a similar formula than (1). However, this probability is the complement of P(G). Mathematically:

$\\ P(NG) = P(NG|H)*P(H) + P(NG|M)*P(M) + P(NG|P)*P(P)$

P(NG|H) = 1 - P(G|H) = 1 - 0.95 = 0.05

P(NG|M) = 1 - P(G|M) = 1 - 0.60 = 0.40

P(NG|P) = 1 - P(G|M) = 1 - 0.10 = 0.90

$\\ P(NG) = 0.05*0.40 + 0.40*0.35 + 0.90*0.25$

$\\ P(NG) = 0.385\;or\; 38.5\%$

Which is equal to

P(NG) = 1 - P(G) = 1 - 0.615 = 0.385

Well, having all this information at hand:

$\\ P(M|NG) = \frac{P(NG|M)*P(M)}{P(NG)}$

$\\ P(M|NG) = \frac{0.40*0.35}{0.385}$

$\\ P(M|NG) = \frac{0.14}{0.385}$

$\\ P(M|NG) = 0.363636... \approx 0.364$

Then, the <em>probability that a new product does not attain a good review and it is a moderately successful product is about </em>0.364 or 36.4%.

8 0

1 year ago