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3 years ago

6

The mass of a radioactive substance follows a continuous exponential decay model, with a decay rate parameter of 9% per day. A s

ample of this radioactive substance has an initial mass of 4.23 kg. Find the mass of the sample after five days.

1 answer:

sergejj [24]3 years ago

5 0

Answer:

5%

Step-by-step explanation:

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X + 4 = 40<br> X = 44<br><br> 23 = x - 6 <br><br> X = 29

valentinak56 [21]

1. X = 36

2. X = 29

7 0

1 year ago

Advandia is a drug used to treat diabetes, but it may cause an increase in heart attacks among a population already susceptible.

sergiy2304 [10]

Answer:

a) The proportions are not form matched-pairs data.

b) The null hypothesis failed to be rejected.

There is not enough evidence to support the claim that there is evidence of a significant increase in the proportion of people who suffer heart attacks when using Avandia compared to other treatments.

Step-by-step explanation:

a) Two data sets are "paired" when the following one-to-one relationship exists between values in the two data sets:

Each data set has the same number of data points.

Each data point in one data set is related to one, and only one, data point in the other data set.

None of this conditions apply in this case, so the proportions are not form matched-pairs data.

b) This is a hypothesis test for the difference between proportions.

The claim is that there is evidence to suggest that there is a significant increase in the proportion of people who suffer heart attacks when using Avandia compared to other treatments.

Then, the null and alternative hypothesis are:

$H_0: \pi_1-\pi_2=0\\\\H_a:\pi_1-\pi_2> 0$

The significance level is 0.05.

The sample 1 (Avindia treatment), of size n1=1456 has a proportion of p1=0.0185.

$p_1=X_1/n_1=27/1456=0.0185$

The sample 2 (other treatment), of size n2=2895 has a proportion of p2=0.0142.

$p_2=X_2/n_2=41/2895=0.0142$

The difference between proportions is (p1-p2)=0.0044.

$p_d=p_1-p_2=0.0185-0.0142=0.0044$

The pooled proportion, needed to calculate the standard error, is:

$p=\dfrac{X_1+X_2}{n_1+n_2}=\dfrac{27+41}{1456+2895}=\dfrac{68}{4351}=0.0156$

The estimated standard error of the difference between means is computed using the formula:

$s_{p1-p2}=\sqrt{\dfrac{p(1-p)}{n_1}+\dfrac{p(1-p)}{n_2}}=\sqrt{\dfrac{0.0156*0.9844}{1456}+\dfrac{0.0156*0.9844}{2895}}\\\\\\s_{p1-p2}=\sqrt{0.00001+0.00001}=\sqrt{0.00002}=0.004$

Then, we can calculate the z-statistic as:

$z=\dfrac{p_d-(\pi_1-\pi_2)}{s_{p1-p2}}=\dfrac{0.0044-0}{0.004}=\dfrac{0.0044}{0.004}=1.1$

This test is a right-tailed test, so the P-value for this test is calculated as (using a z-table):

$P-value=P(z>1.1)=0.1358$

As the P-value (0.1358) is bigger than the significance level (0.05), the effect is not significant.

The null hypothesis failed to be rejected.

There is not enough evidence to support the claim that there is evidence to suggest that there is a significant increase in the proportion of people who suffer heart attacks when using Avandia compared to other treatments.

8 0

3 years ago

Read 2 more answers

Help pleaseeee!!!!!!!!! I’ll mark brainliest!!!!!

Margarita [4]

Answer:

i believe it is D side angle side

Step-by-step explanation:

7 0

3 years ago

Consider the equation Y=-2x+5 Create a table of five ordered pairs that satisfy the equation. What is the slope of the line repr

Vikentia [17]

Five pairs of points (X,Y) that satisfy the equation Y=-2X+5 may be the following:

For X=0: Y=-2*0+5=5 (0,5)

For X=1: Y=-2*1+5=3 (1,3)

For X=2: Y=-2*2+5=1 (2,1)

For X=3: Y=-2*3+5=-1 (3,-1)

For X=4: Y=-2*4+5=-3 (4,-3)

The slope of the function is m=-2. Correct answer: C

5 0

3 years ago

A musician spends 90 minutes practicing piano and guitar the time spent is 30 minute less than twice the same time spent on guit

11111nata11111 [884]

Answer:

The which spends on the piano is( 50 minutes )

The which spends on the guitar is( 40 minutes )

Step-by-step explanation:

The steps of the solution in the above photo

I hope that is useful for you :)

8 0

3 years ago