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Svetllana [295]

3 years ago

11

The half life of a radioactive kind of cadmium is 14 years. How much will be left after 28 years, if you start with 72 grams of

it?

1 answer:

nlexa [21]3 years ago

8 0

Answer:

18 grams

Step-by-step explanation:

You might be interested in

Find the 10th and nth term of each G.P.:5,25,125,.....

RUDIKE [14]

Answer:

The $n^{th}$ of the sequence

$t_{n} = ar^{n-1}$

The $10^{th}$ of the sequence

$t_{10} = 5(5)^{10-1} = 9,765,625$

Step-by-step explanation:

<u><em>Explanation:-</em></u>

Given that the geometric sequence

5, 25 , 125 ,....

First-term a= 5

Difference $r = \frac{25}{5} =5$

The $n^{th}$ of the sequence

$t_{n} = ar^{n-1}$

The $10^{th}$ of the sequence

$t_{10} = 5(5)^{10-1} = 9,765,625$

6 0

3 years ago

A 2.7 meter ladder leans against a house forming

mrs_skeptik [129]

Answer:

1.35m

Step-by-step explanation:

A 2.7 meter ladder leans against a house forming a 30° angle with the house. Exactly how far is the base of the ladder from the house?

We solve the above question using the Trigonometric function of Sine

cos theta = Opposite/Hypotenuse

From the question

Opposite = Distance of base of the ladder from the house = x

Hypotenuse = Length of the ladder = 2.7m

Theta = 30°

Hence,

sin 30 = x/2.7 m

Cross Multiply

x = sin 30 × 2.7m

x = 1.35m

Option b is correct.

3 0

3 years ago

A prison official wants to estimate the proportion of cases of recidivism. Examining the records of 250 convicts, the official d

son4ous [18]

Answer:

For this sample, the estimated standard error is of 0.0277

Step-by-step explanation:

Central Limit Theorem

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean $\mu$ and standard deviation $\sigma$ , the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$ .

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean $\mu = p$ and standard deviation $s = \sqrt{\frac{p(1-p)}{n}}$

Examining the records of 250 convicts, the official determines that there are 65 cases of recidivism.

This means that $n = 250, p = \frac{65}{250} = 0.26$

For this sample, the estimated standard error is

$s = \sqrt{\frac{p(1-p)}{n}} = \sqrt{\frac{0.26*0.74}{250}} = 0.0277$

For this sample, the estimated standard error is of 0.0277

4 0

3 years ago

Ivenika [448]

Answer:

I believe that the first 9 (90) is 100 times greater than the second 9 (9000).

Step-by-step explanation:

If you multiply 90 by 10, it will get 900, which is not enough!

5 0

3 years ago

A rectangular sheet of cardboard measures 12.2cm by 5.6cm. What is the radius of the largest circle that can be cut from the car

Alinara [238K]

6.1cm is the right answer.

4 0

3 years ago