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4 years ago

Write down the value of x = 65 give your reason for your answer

Mathematics

1 answer:

densk [106]4 years ago

8 0

Where is the question?

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Find sum of three consecutive even integers if the largest integer is Y

KATRIN_1 [288]

Answer:

3y -- 6

Step-by-step explanation:

if the largest number is y, then the other two integers would be (y -- 2) and (y -- 4).

Therefore the sum of the integers would be

y + (y -- 2) + (y -- 4) = 3y -- 6.

7 0

3 years ago

Find the angle whose cosine is .4203

ludmilkaskok [199]

The cosine of 1.137020412 degrees is 0.4204.

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3 years ago

The brand manager for a brand of toothpaste must plan a campaign designed to increase brand recognition. He wants to first deter

VMariaS [17]

Answer:

He must survey 123 adults.

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of $\pi$ , and a confidence level of $1-\alpha$ , we have the following confidence interval of proportions.

$\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}$

In which

z is the z-score that has a p-value of $1 - \frac{\alpha}{2}$ .

The margin of error is:

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

Assume that a recent survey suggests that about 87% of adults have heard of the brand.

This means that $\pi = 0.87$

90% confidence level

So $\alpha = 0.1$ , z is the value of Z that has a p-value of $1 - \frac{0.1}{2} = 0.95$ , so $Z = 1.645$ .

How many adults must he survey in order to be 90% confident that his estimate is within five percentage points of the true population percentage?

This is n for which M = 0.05. So

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

$0.05 = 1.645\sqrt{\frac{0.87*0.13}{n}}$

$0.05\sqrt{n} = 1.645\sqrt{0.87*0.13}$

$\sqrt{n} = \frac{1.645\sqrt{0.87*0.13}}{0.05}$

$(\sqrt{n})^2 = (\frac{1.645\sqrt{0.87*0.13}}{0.05})^2$

$n = 122.4$

Rounding up:

He must survey 123 adults.

6 0

3 years ago

Given that Triangle ABC ~ DEF, solve for X.

Vadim26 [7]

Answer:

x = 7

Step-by-step explanation:

if ABC ~ DEF than AB ~ ED, AC ~ DF, and CB ~ FE

The ratio of AB to ED is given as 5/30 = 1/6

For AC ~ ED the ratio would be same x/42 = 1/6 cross multiply it

6x = 42

x = 7

6 0

3 years ago

8,-1,-5,2? Which one!.............

Lunna [17]

Answer: I would say -8,-1

Step-by-step explanation:

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3 years ago