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3 years ago

A sample has a half-life of 1000 years. 1/2 of the isotopes are parents. How old is it?

Mathematics

2 answers:

Zina [86]3 years ago

8 0

The correct answer is A

8_murik_8 [283]3 years ago

6 0

The answer is A you just divide the numbers

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What is this value? giving thanks and marking brainliest :)

Pachacha [2.7K]

Answer:

x = 23 degress

Step-by-step explanation:

(x + 2) + 65 = 90

x + 2 = 25

x = 23 degress

4 0

3 years ago

Can someone please help me

liraira [26]

To calculate the areas i’m pretty sure u need to do L x W so it would be .. 644 in2?

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3 years ago

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Write the equation 2x - 3y = 6 in slope-intercept form.

ExtremeBDS [4]

Answer:

$y = \frac{ 2}{ 3} x - 2$

Step-by-step explanation:

$2x - 3y = 6 \\ - 3y = - 2x + 6 \\ \\ y = \frac{ - 2}{ - 3} x + \frac{6}{ - 3} \\ \\ \huge \purple{ \boxed{ y = \frac{ 2}{ 3} x - 2}} \\ this \: is \: in \: the \: slope - intercept \: form.$

5 0

3 years ago

Read 2 more answers

Data is collected to compare two different types of batteries. We measure the time to failure of 12 batteries of each type. Batt

-Dominant- [34]

Using the t-distribution, it is found that since the test statistic is greater than the critical value for the right-tailed test, it is found that there is enough evidence to conclude that Battery B outlasts Battery A by more than 2 hours.

At the null hypothesis, it is tested if it does not outlast by more than 2 hours, that is, the subtraction is not more than 2:

$H_0: \mu_B - mu_A \leq 2$

At the alternative hypothesis, it is tested if it outlasts by more than 2 hours, that is:

$H_1: \mu_B - \mu_A > 2$

The sample means are: $\mu_A = 8.65, \mu_B = 11.23$

The standard deviations for the samples are $s_A = s_B = 0.67$

Hence, the standard errors are:

$s_{Ea} = S_{Eb} = \frac{0.67}{\sqrt{12}} = 0.1934$

The distribution of the difference has mean and standard deviation given by:

$\overline{x} = \mu_B - \mu_A = 11.23 - 8.65 = 2.58$

$s = \sqrt{s_{Ea}^2 + s_{Eb}^2} = \sqrt{0.1934^2 + 0.1934^2} = 0.2735$

The test statistic is given by:

$t = \frac{\overline{x} - \mu}{s}$

In which $\mu = 2$ is the value tested at the hypothesis.

Hence:

$t = \frac{\overline{x} - \mu}{s}$

$t = \frac{2.58 - 2}{0.2735}$

$t = 2.12$

The critical value for a right-tailed test, as we are testing if the subtraction is greater than a value, with a 0.05 significance level and 12 + 12 - 2 = 22 df is given by $t^{\ast} = 1.71$

Since the test statistic is greater than the critical value for the right-tailed test, it is found that there is enough evidence to conclude that Battery B outlasts Battery A by more than 2 hours.

A similar problem is given at brainly.com/question/13873630

7 0

3 years ago

A set of 25 two digit numbers are listed below 10,17,20,23,24,28,32,39,42,25,26,52,55,58,61,65,66,72,75,78,79,85,94,97,98. What

eimsori [14]

Answer:

0.48

Step-by-step explanation:

Given the data:

10,17,20,23,24,28,32,39,42,25,26,52,55,58,61,65,66,72,75,78,79,85,94,97,98

Sum of each of the numbers :

1, 8, 2, 5, 6, 10, 6, 12, 6, 7, 8, 7, 20, 13, 7, 11, 12, 9, 12, 15, 16, 13, 13, 16, 17

Probability that sum of the number's digit is odd:

Number of odd sum / total numbers

Number of odd sum = 12

Total numbers = 25

12 / 25

= 0.48

3 0

3 years ago