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1 year ago

10

An element with a mass of 320 grams decays by 5.1% per minute. To the nearest tenth of a minute, how long will it be until there

are 200 grams of the element remaining?

1 answer:

HACTEHA [7]1 year ago

7 0

Answer:

X=9

Step-by-step explanation:

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Two processes are used to produce forgings used in an aircraft wing assembly. Of 200 forgings selected from process 1, 10 do not

tangare [24]

Answer:

a.

$\bar p_1=0.05\\\bar p_2=0.067$

b-Check illustration below

c.(-0.0517,0.0177

Step-by-step explanation:

a.let $p_1 \& p_2$ denote processes 1 & 2.

For $p_1$ : T1=10,n1=200

For $p_2$ :T2=20,n2=300

Therefore

$\bar p_1=\frac{t_1}{N_1}=\frac{10}{200}=0.05\\\bar p_2=\frac{t_2}{N_2}=\frac{20}{300}=0.067$

b. To test for hypothesis:-

i.

$H_0:p_1=p_2\\H_A=p_1\neq p_2\\\alpha=0.05$

ii.For a two sample Proportion test

$Z=\frac{\bar p_1-\bar p_2}{\sqrt(\bar p(1-\bar p)(\frac{1}{n_1}+\frac{1}{n_2})}\\$

iii. for $\frac{\alpha}{2}=(-1.96,+1.96)$ (0.5 alpha IS 0.025),

reject $H_o$ if $|Z|>1.96$

iv. Do not reject $H_o$ . The noncomforting proportions are not significantly different as calculated below:

$z=\frac{0.050-0.067}{\sqrt {(0.06\times0.94)\times \frac{1}{500}}}$

z=-0.78

c. $(1-\alpha).100\%$ for the p1-p2 is given as:

$(\bar p_1-\bar p_2)\pm Z_0_._5_\alpha \times \sqrt \frac{ \bar p_1(1-\bar p_1)}{n_1}+\frac{\bar p_2(1-\bar p_2)}{n_2}\\\\=(0.05-0.067)\pm 1.645 \times \sqrt \ \frac{0.05+0.95}{200}+\frac{0.067+0.933}{300}\\$

=(-0.0517,+0.0177)

*CI contains o, which implies that proportions are NOT significantly different.

4 0

2 years ago

The New Haven High School cheerleaders got a t-shirt gun. The cheerleaders stand

nevsk [136]

Answer: the gun was held 4ft high i.e H = 4ft

Step-by-step explanation:

To determine how high the gun was held when it was fired H;

Before firing the t-shirt up, the gun and the t-shirt are both at the same height.

Therefore,

H = h(0) i.e h(t) at t = 0

h(t) = -16t^2 + 64t + 4

H = h(0) = -16(0)^2 + 64(0) + 4

H = 4ft

7 0

2 years ago

If the area of the rectangle is given by the polynomial 2x^2-7x-15, what is the dimension of the reactangle in terms of x?

Irina18 [472]

Answer:

x - 5 and 2x + 3

Step-by-step explanation:

<h3>Given</h3>

Area of rectangle = 2x^2 - 7x - 15

<h3>To find</h3>

Dimensions of rectangle

<h3>Solution</h3>

<u>Since the area is the product of the sides, let's try to factorize the given:</u>

2x^2 - 7x - 15=
2x^2 - 10x + 3x - 15 =
2x(x - 5) + 3(x - 5) =
(x - 5)(2x + 3)

<u>So the dimensions are:</u>

x - 5 and 2x + 3

4 0

1 year ago

Adita has two options for how to invest $1,000. Plan A: Put the $1,000 in an account that pays $100 per year. Plan B: Put the $1

cluponka [151]

Answer:

Plan A = 1000 dollars to be invested in an account that pays 100 dollars per year. (1000 + 100 = 1100 dollars in a year)

Plab B = 1000 dollars to be invested in an account that pays 5% interests per year (1000 * .05 = 50 => 1000 + 50 = 1050 dollars per year)

The correct answer is Plan A will be worth more than plan B after two years.

Step-by-step explanation:

Plan A = 1000 dollars to be invested in an account that pays 100 dollars per year. (1000 + 100 = 1100 dollars in a year)

Plab B = 1000 dollars to be invested in an account that pays 5% interests per year (1000 * .05 = 50 => 1000 + 50 = 1050 dollars per year)

3 0

1 year ago

The marketing manager of a branch office of a local telephone operating company wants to study the characteristics of residentia

charle [14.2K]

Answer:

No. There is not enough evidence to support the claim that the population standard deviation is different from $12.

Step-by-step explanation:

The null hypothesis is that the true standard deviation is 12.

The alternative hypothesis is that the true standard deviation differs from 12.

We can state:

$H_0: \sigma=12\\\\H_a: \sigma\neq12$

The significance level is 0.10.

The sample size is n=15, so the degrees of freedom are:

$df=n-1=15-1=14$

The sample standard deviation is 9.25.

The test statistic is

$T=(n-1)(s/\sigma_0)^2=14*(9.25/12)^2=14*0.77^2=14*0.59=8.32$

The critical values for rejecting the null hypothesis are:

$\chi_{0.025,13}=5.00875\\\\\chi_{0.975,13}=24.7356$

As T=8.32 is within the acceptance region (5.01, 24.74), the null hypothesis failed to be rejected.

There is not enough evidence to support the claim that the population standard deviation is different from $12.

8 0

1 year ago