Circumference of a semi-circle with diameter 30

Express each of the following radios in the simplest form.

AURORKA [14]

Answer:

hope it helps man

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Step-by-step explanation:

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4 0

2 years ago

Two brands of AAA batteries are tested in order to compare their voltage. The data summary can be found below.

garik1379 [7]

Answer:

The 95% confidence interval would be given by $0.281 \leq \mu_1 -\mu_2 \leq 0.529$

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

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".

$\bar X_1 =9.2$ represent the sample mean 1

$\bar X_2 =8.8$ represent the sample mean 2

n1=27 represent the sample 1 size

n2=30 represent the sample 2 size

$\sigma_1 =0.3$ population standard deviation for sample 1

$\sigma_2 =0.1$ population standard deviation for sample 2

$\mu_1 -\mu_2$ parameter of interest.

Solution to the problem

The confidence interval for the difference of means is given by the following formula:

$(\bar X_1 -\bar X_2) \pm z_{\alpha/2}\sqrt{\frac{\sigma^2_1}{n_1}+\frac{\sigma^2_2}{n_2}}$ (1)

The point of estimate for $\mu_1 -\mu_2$ is just given by:

$\bar X_1 -\bar X_2 =9.2-8.8=0.4$

Since the Confidence is 0.95 or 95%, the value of $\alpha=0.05$ and $\alpha/2 =0.025$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-NORM.INV(0.025,0,1)".And we see that $t_{\alpha/2}=1.96$

Now we have everything in order to replace into formula (1):

$0.4-1.96\sqrt{\frac{0.3^2}{27}+\frac{0.1^2}{30}}=0.281$

$0.4+1.96\sqrt{\frac{6^2}{36}+\frac{7^}{49}}=0.519$

So on this case the 95% confidence interval would be given by $0.281 \leq \mu_1 -\mu_2 \leq 0.529$

6 0

3 years ago

Wilmer already has 214 cards. he needs to collect 334 cards. he plans to collect 8 cards each day. find the minimum number of da

Wittaler [7]

The answer is 15 days.

The first step you need to take is to subtract the amount of cards he has from the amount of cards he needs. So 334 (needs) - 214(has) = 120 cards he still needs. So he is collecting 8 cards a day. In order to find out how many days it will take to collect the 120 cards, we need to divide 120 by 8. 120 divided by 8 is 15. So it will take 15 days collecting 8 cards a day in order to reach the 120 cards he still needs to collect.

3 0

3 years ago

The owner of the Outdoor Furniture Center decides to use the 120% markup. At the end on

lana66690 [7]

Answer: The total price of a bench is 1.008x.

Step-by-step explanation:

Since we have given that

Let the cost price be 'x'.

Mark up % = 120%

So, Mark up value would be

$\dfrac{120}{100}x\\\\=1.20x$

Discount % = 20%

Amount of discount is given by

$\dfrac{20}{100}\times 1.2x\\\\=0.2\times 1.2x\\\\=0.24x$

So, it becomes,

Amount after discount is given by

$1.2x-0.24x\\\\=0.96x$

Sales tax = 5%

Amount of sales tax would be

$\dfrac{100+5}{100}\times 0.96x\\\\=\dfrac{105}{100}\times 0.96x\\\\=1.05\times 0.96x\\\\=1.008x$

Hence, the total price of a bench is 1.008x.

6 0

3 years ago

Pls send me step by step pic

Thepotemich [5.8K]

To solve, simply do this:

$(\frac{1}{2}^3)-(\frac{3}{4} )^2\\\\\frac{1}{2} *\frac{1}{2} *\frac{1}{2} *\frac{1}{2} \\\\\frac{1}{8} -(\frac{3}{4})^2\\\\\frac{1}{8}-\frac{9}{16}\\\\=\frac{-7}{16}$

Then you'll get the answer, -7/16

7 0

3 years ago