The expression 3 x 7 - 4x8+2 is equivalent to which of the following?

The measurenicnt of the circumference of a circle is found to be 56 centimeters. The possible error in measuring the circumferen

BartSMP [9]

Answer:

(a) Approximate the percent error in computing the area of the circle: 4.5%

(b) Estimate the maximum allowable percent error in measuring the circumference if the error in computing the area cannot exceed 3%: 0.6 cm

Step-by-step explanation:

(a)

First we need to calculate the radius from the circumference:

$c=2\pi r\\r=\frac{c}{2\pi } \\c=8.9 cm$

I leave only one decimal as we need to keep significative figures

Now we proceed to calculate the error for the radius:

$\Delta r=\frac{dt}{dc} \Delta c\\\\\frac{dt}{dc} = \frac{1}{2 \pi } \\\\\Delta r=\frac{1}{2 \pi } (1.2)\\\\\Delta r= 0.2 cm$

$r = 8.9 \pm 0.2 cm$

Again only one decimal because the significative figures

Now that we have the radius, we can calculate the area and the error:

$A=\pi r^{2}\\A=249 cm^{2}$

Then we calculate the error:

$\Delta A= (\frac{dA}{dr} ) \Delta r\\\\\Delta A= 2\pi r \Delta r\\\\\Delta A= 11.2 cm^{2}$

$A=249 \pm 11.2 cm^{2}$

Now we proceed to calculate the percent error:

$\%e =\frac{\Delta A}{A} *100\\\\\%e =\frac{11.2}{249} *100\\\\\%e =4.5\%$

(b)

With the previous values and equations, now we set our error in 3%, so we just go back changing the values:

$\%e =\frac{\Delta A}{A} *100\\\\3\%=\frac{\Delta A}{249} *100\\\\\Delta A =7.5 cm^{2}$

Now we calculate the error for the radius:

$\Delta r= \frac{\Delta A}{2 \pi r}\\\\\Delta r= \frac{7.5}{2 \pi 8.9}\\\\\Delta r= 0.1 cm$

Now we proceed with the error for the circumference:

$\Delta c= \frac{\Delta r}{\frac{1}{2\pi }} = 2\pi \Delta r\\\\\Delta c= 2\pi 0.1\\\\\Delta c= 0.6 cm$

5 0

4 years ago

What does 10+q equal?

BlackZzzverrR [31]

Answer:

Well if no variable substitution is given its 10+q

10+q=10+q

7 0

3 years ago

Read 2 more answers

Directions: Simplify these problems by combining like terms.

Verdich [7]

Answer:

6s + 2s - 3s - 6:

5s-6

10t - 4t -6 + 5t:

11t-6

18r + 18r + 9r - 3r:

42r

20 - 4q + 40r - 16:

-4q+40r+4

17st - 16s + t:

17st-16s+t

. 101+101x - x:

101+100x

16a2 - 14a + a2 - 3a:

14 ato the power of 2- 17a

14t + 14t + t:

29t

r + s + rs + s + rs + s:

r+2rs+3s

54 pt - 3p + 4t - 3pt:

51pt-3p+4t

i dont know 11

101c - 5c +4c:

100c

12q - 4 + 10q - 4q +9:

18q+5

21k - 20k + 3k:

4k

181x + 91x - 23x:

249x

Step-by-step explanation:

3 0

2 years ago

Read 2 more answers

There were 3 apple, 1 mixed fruit, 2 grape, and 4 tropical fruit juice boxes in the cooler at the picnic. What is the probabilit

goldenfox [79]

There are 10 juice boxes in the cooler altogether.
2 of them are grape.

The first time Jill pulls one out with her eyes closed,
the probability that it's a grape is

2 / 10 .

If that try is successful, then there are 9 boxes left in the cooler,
and one of them is grape.

If she already has one grape, and reaches in again with her eyes
closed, the probability of pulling out the second grape is

1 / 9 .

The probability of both events happening in two tries is

(2/10) x (1/9) = 2/90 = 1/45 = (2 and 2/9) percent .

6 0

3 years ago

Read 2 more answers

The manager of the customer service division of a major consumer electronics company is interested in determining whether the cu

PolarNik [594]

The best sampling strategy would be a stratified sample.

<h3>How are samples classified?</h3>

Samples may be classified as:

Convenient: Drawn from a conveniently available pool.

Random: All the options into a hat and drawn some of them.

Systematic: Every kth element is taken.

Cluster: Divides population into groups, called clusters, and each element in the cluster is surveyed.

Stratified: Also divides the population into groups. Then, a equal proportion of each group is surveyed.

For this problem, the 4 different brands of the recorders must be considered, hence the buyers should be divided into groups, and a proportion of each group should be sampled, hence a stratified sample should be used.

More can be learned about sampling at brainly.com/question/25122507

#SPJ1

3 0

2 years ago