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2 years ago

Can someone please help with my maths homework? I need to estimate the value of 102.3 / 4.7

2 answers:

6 0

The answer would be 20.

102.3 can be rounded down to 100 and 4.7 can be rounded up to 5. 100 divides by 5 is 20.

The trick is to find the 2 closest numbers that you can do mental math with.

anyanavicka [17]2 years ago

3 0

OK - convert the 2 numbers to one significant figure:-

102.3 = 100
4.7 = 5

So the estimate is 100/5 = 20 answer

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David spent 10 days at summer camp. Each day he spent 4 hours at Arts and

horsena [70]

Answer: David made 120 drawings while at summer camp

4 0

2 years ago

Let us suppose we have data on the absorbency of paper towels that were produced by two different manufacturing processes. From

maksim [4K]

Answer:

The 95% CI for the difference of means is:

$-155.45 \leq \mu_1-\mu_2 \leq -44.55$

Step-by-step explanation:

The question is incomplete:

"Find a 95% confidence interval on the difference of the towels mean absorbency produced by the two processes. Assumed that the standard deviations are estimated from the data. Round to two decimals places."

Process 1:

- Sample size: 10

- Mean: 200

- S.D.: 15

Process 2:

- Sample size: 4

- Mean: 300

- S.D.: 50

The difference of the sample means is:

$M_d=M_1-M_2=200-300=-100$

The standard deviation can be estimated as:

$\sigma_d=\sqrt{\frac{\sigma_1^2}{n_1}+\frac{\sigma_2^2}{n_2}}\\\\\sigma_d=\sqrt{\frac{15^2}{10}+\frac{50^2}{4}} =\sqrt{22.5+625}=\sqrt{647.5}=25.45$

The degrees of freedom are:

$df=n_1+n_2-2=10+4-2=12$

The t-value for a 95% confidence interval and 12 degrees of freedom is t=±2.179.

Then, the confidence interval can be written as:

$M_d-t\cdot \sigma_d\leq \mu_1-\mu_2 \leq M_d+t\cdot \sigma_d\\\\-100-2.179*25.45\leq \mu_1-\mu_2 \leq -100+2.179*25.45\\\\-100-55.45 \leq \mu_1-\mu_2 \leq -100+55.45\\\\ -155.45 \leq \mu_1-\mu_2 \leq -44.55$

8 0

3 years ago

Round to the nearest hundred. 367 +319

Naily [24]

Answer:

686 becomes 700

Step-by-step explanation:

367+319 = 686

hundreds tens one

6 8 6

We are rounding to the hundreds places

We have to look at the tens place

8>=5 so we will round up

6 becomes 7

686 becomes 700

6 0

2 years ago

Sue bought two pairs of jeans and a belt that costs $6.95 the tax on the items was $5.85 sue pay the cashier $70 how much money

yaroslaw [1]

cost of two pair of jeans- $55
cost of belt-$ 5.85
tax- $5.85
total bill- $67.8
as sue paid $70 to the cashier for the bill amount so she will get $2.2 change in return.

6 0

3 years ago

William bought some tickets to see his favorite singer. He bought some adult tickets and some children tickets, for a total of 1

Viefleur [7K]

Hello!

Let 'a' stand for adult tickets and 'c' for children tickets.

a + c = 15

(Both adult and children tickets make up a total of 15 tickets).

30a + 20c = 330

a = 3

c = 12

A N S W E R:

William bought 3 adults tickets and 12 children's tickets.

5 0

3 years ago