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3 years ago

Help me plsssssssssssss

Mathematics

1 answer:

LUCKY_DIMON [66]3 years ago

6 0

Answer:

The radius is 5 cm

Step-by-step explanation:

The formula for the area of a circle is : $\p*radius^2$

To work out the length of the radius you would first need to divide the area of 78.5 cm by pi (pi=3.14), this gives you $25cm^2\\$ . This is because by dividing the area by pi we are isolating the value of the radius squared.

The final step is to work out the radius. You can do this by finding the square root of the radius squared which is 25, this gives you 5 cm. This means that the radius is 5 cm. This is because the square root is a number that when squared equals that number.

1) Divide 78.5 by pi.

$78.5/\pi=25cm^2$

2) Find the square root of 25 cm squared.

$\sqrt{25} =5 cm$

In this question pi is 3.14

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A sample of 16 small bags of the same brand of candies was selected. Assume that the population distribution of bag weights is n

Olegator [25]

Answer:

i) $2 - 1.64 \frac{0.1}{\sqrt{16}}= 1.959$

$2 + 1.64 \frac{0.1}{\sqrt{16}}= 2.041$

So then the 90% confidence interval is given by (1.959, 2.041)

ii) Figure attached

iii) $ME= 1.64 *\frac{0.1}{\sqrt{16}}= 0.041$

Step-by-step explanation:

Previous concepts

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The confidence interval is given by this formula:

$\bar X \pm z_{\alpha/2} \frac{\sigma}{\sqrt{n}}}$ (1)

And for a 90% of confidence the significance is given by $\alpha=1-0.9=0.1$ , and $\frac{\alpha}{2}=0.05$ . Since we know the population standard deviation we can calculate the critical value $z_{0.05}= \pm 1.64$

We know the folllowing data:

$\bar X = 2$ represent the sample mean

$\sigma = 0.1$ represent the population deviation

n =16 represent the sample size

Part i)

If we replace the values given into formula (1) we got:

$2 - 1.64 \frac{0.1}{\sqrt{16}}= 1.959$

$2 + 1.64 \frac{0.1}{\sqrt{16}}= 2.041$

So then the 90% confidence interval is given by (1.959, 2.041)

Part ii)

Figure attached. We have the illustration for the confidence interval obtained.

Part iii)

The margin of error is given by:

$ME=z_{\alpha/2} \frac{\sigma}{\sqrt{n}}}$

And if we replace we got:

$ME= 1.64 *\frac{0.1}{\sqrt{16}}= 0.041$

3 0

3 years ago

Given that 3x – 4y= 22<br> -<br> Find & when y = -7

Liono4ka [1.6K]

<h2>Answer:</h2>

x=2

<h2><em><u>Step-by-step explanation:</u></em></h2>

6 0

2 years ago

A welder produces 7 welded assemblies during the first day on a new job, and the seventh assembly takes 45 minutes (unit time).

likoan [24]

Answer:

(a). 72.9%.

(b). 13.6 hr.

Step-by-step explanation:

So, we are given the following data or parameters or information which is going to assist us in solving this question/problem;

=> "A welder produces 7 welded assemblies during the first day on a new job, and the seventh assembly takes 45 minutes (unit time). "

=> The worker produces 10 welded assemblies on the second day, and the 10th assembly on the second day takes 30 minutes"

So, we will be making use of the Crawford learning curve model.

T(7) + 10 = T (17) = 30 min.

T(7) = T1(7)^b = 45.

T(17 ) = T1(17)^b = 30.

(T1) = 45/7^b = 30/17^b.

45/30 = 7^b/17^b = (7/17)^b.

1.5 = (0.41177)^b.

ln 1.5 = b ln 0.41177.

0.40547 = -0.8873 b.

b = - 0.45696.

=> 2^ -0.45696 = 0.7285.

= 72.9%.

(b). T1= 45/7^ - 045696 = 109.5 hr.

V(TT)(17) = 109.5 {(17.51^ - 0.45696 – 0.51^ - 0.45696) / (1 - 0.45696)} .

V(TT) (17) = 109.5 {(4.7317 - 0.6863) / 0.54304} .

= 815.7 min .

= 13.595 hr.

8 0

3 years ago

Pls help me or me fail

Mrac [35]

Answer:

Cumin has the least price per ounce

Step-by-step explanation:

1. Divide each spice price to the size

Cumin -> 4.80/1.5= 3.2

Ginger -> 3.60/ 0.8= 4.5

Nutmeg -> 6.30/ 1.8= 3.5

Thyme -> 4.50/ 1.25= 3.6

5 0

3 years ago

A rectangular swimming pool has a base of 200 square feet. The pool has a depth of 5 feet.

xz_007 [3.2K]

Answer:

1,000 ft³

Step-by-step explanation:

The volume is given by ...

V = Bh

where B is the area of the base, and h is the height. For the given dimensions, the volume is ...

V = (200 ft²)(5 ft) = 1000 ft³

3 0

2 years ago