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3 years ago

Explain how an estimate helps you to place the decimal point when mutiplyning 3.9 times 5.3

2 answers:

7 0

It'll make it easier to multiply. If you round 3.9 to four, and 5.3 to five, it's quite easy to figure out the answer is about 20. I hope this helps! :)

Juli2301 [7.4K]3 years ago

6 0

You can round these numbers to the closes whole number; 3.9-->4 and 5.3-->5, and then you can do 5x4 to get 20; and if you multiply regularly without estimating, your answer will be around 20.

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Convert each fraction to a decimal 6/8=0._____

JulijaS [17]

I think it's 6.80 hope it helped

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The graph below shows the path of a model rocket after its launch from the ground.

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2 years ago

On a certain hot summer day, 481 people used the public swimming pool. The daily prices are 1.25 for children and 2.25 for adult

spayn [35]

Answer:the number of children that swam in the public pool that day is 222

the number of adult that swam in the public pool that day is 259

Step-by-step explanation:

Let x represent the number of children that swam in the public pool that day.

Let y represent the number of adult that swam in the public pool that day.

On a certain hot summer day, 481 people used the public swimming pool. This means that

x + y = 481

The daily prices are 1.25 for children and 2.25 for adults. The receipts for admission totaled to 86.25. This means that

1.25x + 2.25y = 860.25 - - - - - - - -1

Substituting x = 481 - y into equation 1, it becomes

1.25(481 - y) + 2.25y = 860.25

601.25 - 1.25y + 2.25y = 860.25

- 1.25y + 2.25y = 860.25 - 601.25

y = 259

Substituting y = 259 into x = 481 - y, it becomes

x = 481 - 259

x = 222

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3 years ago

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olchik [2.2K]

Answer:

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Step-by-step explanation:

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3 years ago

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The computers of nine engineers at a certain company are to be replaced. Four of the engineers have selected laptops and the oth

Gala2k [10]

Answer:

(a) There are 70 different ways set up 4 computers out of 8.

(b) The probability that exactly three of the selected computers are desktops is 0.305.

Step-by-step explanation:

Of the 9 new computers 4 are laptops and 5 are desktop.

Let X = a laptop is selected and Y = a desktop is selected.

The probability of selecting a laptop is = $P(Laptop) = p_{X} = \frac{4}{9}$

The probability of selecting a desktop is = $P(Desktop) = p_{Y} = \frac{5}{9}$

Then both X and Y follows Binomial distribution.

$X\sim Bin(9, \frac{4}{9})\\ Y\sim Bin(9, \frac{5}{9})$

The probability function of a binomial distribution is:

$P(U=k)={n\choose k}\times(p)^{k}\times (1-p)^{n-k}$

(a)

Combination is used to determine the number of ways to select k objects from n distinct objects without replacement.

It is denotes as: ${n\choose k}=\frac{n!}{k!(n-k)!}$

In this case 4 computers are to selected of 8 to be set up. Since there cannot be replacement, i.e. we cannot set up one computer twice or thrice, use combinations to determine the number of ways to set up 4 computers of 8.

The number of ways to set up 4 computers of 8 is:

${8\choose 4}=\frac{8!}{4!(8-4)!}\\=\frac{8!}{4!\times 4!} \\=70$

Thus, there are 70 different ways set up 4 computers out of 8.

(b)

It is provided that 4 computers are randomly selected.

Compute the probability that exactly 3 of the 4 computers selected are desktops as follows:

$P(Y=3)={4\choose 3}\times(\frac{5}{9})^{3}\times (1-\frac{5}{9})^{4-3}\\=4\times\frac{125}{729}\times\frac{4}{9}\\ =0.304832\\\approx0.305$

Thus, the probability that exactly three of the selected computers are desktops is 0.305.

(c)

Compute the probability that of the 4 computers selected at least 3 are desktops as follows:

$P(Y\geq 3)=1-P(Y$

Thus, the probability that at least three of the selected computers are desktops is 0.401.

6 0

3 years ago