All categories

3 years ago

A tire rotates

1 answer:

7 0

$450\ rot/min=450\ rot/60s=\frac{450}{60}\ rot/s=7.5\ rot/min\\\\7.5\cdot360^o=2700^o\leftarrow answer$

$7.5\to7\ and\ half\ circle\to 180^o$

You might be interested in

An educational psychologist wishes to know the mean number of words a third grader can read per minute. She wants to make an est

malfutka [58]

Answer:

99% confidence interval for the true mean number of words a third grader can read per minute is [35.5 , 35.9].

Step-by-step explanation:

We are given that a sample of 1584 third graders, the mean words per minute read was 35.7. Assume a population standard deviation of 3.3.

Firstly, the pivotal quantity for 99% confidence interval for the population mean is given by;

P.Q. = $\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }$ ~ N(0,1)

where, $\bar X$ = sample mean words per minute read = 35.7

$\sigma$ = population standard deviation = 3.3

n = sample of third graders = 1584

$\mu$ = population mean number of words

<em>Here for constructing 99% confidence interval we have used One-sample z test statistics as we know about the population standard deviation.</em>

<em />

So, 99% confidence interval for the population mean, $\mu$ is ;

P(-2.58 < N(0,1) < 2.58) = 0.99 {As the critical value of z at 0.5% level

of significance are -2.58 & 2.58}

P(-2.58 < $\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }$ < 2.58) = 0.99

P( $-2.58 \times {\frac{\sigma}{\sqrt{n} } }$ < ${\bar X-\mu}$ < $2.58 \times {\frac{\sigma}{\sqrt{n} } }$ ) = 0.99

P( $\bar X-2.58 \times {\frac{\sigma}{\sqrt{n} } }$ < $\mu$ < $\bar X+2.58 \times {\frac{\sigma}{\sqrt{n} } }$ ) = 0.99

<u>99% confidence interval for</u> $\mu$ = [ $\bar X-2.58 \times {\frac{\sigma}{\sqrt{n} } }$ , $\bar X+2.58 \times {\frac{\sigma}{\sqrt{n} } }$ ]

= [ $35.7-2.58 \times {\frac{3.3}{\sqrt{1584} } }$ , $35.7+2.58 \times {\frac{3.3}{\sqrt{1584} } }$ ]

= [35.5 , 35.9]

Therefore, 99% confidence interval for the true mean number of words a third grader can read per minute is [35.5 , 35.9].

6 0

3 years ago

Sam bought a car for $25,000 in 2009. Since then the car has depreciated in value by $1,500 a year. Write a function that will a

lesantik [10]

Answer: The car has a value of $17,500.

Explanation: The car was originally bought at $25,000 and was depreciated over 5 years by $1,500 a year. Over 5 years, the car would be depreciated by a total of $7,500 because $1,500 x 5 years equals $7,500 in total. Since you would distract the total depreciation cost from the original value to find the current value of the car, after 5 year of use, the car would be worth $17,500.

7 0

3 years ago

Please help me solve this exercise.!!

Volgvan

<h3>Answer: -4/3</h3>

=============================================================

Explanation:

Let's square both sides and do a bit of algebra to get the following.

$\sin(x) + \cos(x) = 1/5\\\\\left(\sin(x) + \cos(x)\right)^2 = \left(1/5\right)^2\\\\\sin^2(x) + 2\sin(x)\cos(x) + \cos^2(x) = 1/25\\\\\sin^2(x) + \cos^2(x) + 2\sin(x)\cos(x) = 1/25\\\\1 + 2\sin(x)\cos(x) = 1/25\\\\\sin(2x) = 1/25 - 1\\\\\sin(2x) = 1/25 - 25/25\\\\\sin(2x) = -24/25\\\\$

Now apply the pythagorean trig identity to determine cos(2x) based on this. You should find that cos(2x) = -7/25

This then means tan(2x) = sin(2x)/cos(2x) = 24/7.

From here, you'll use this trig identity

$\tan(2x) = \frac{2\tan(x)}{1-\tan^2(x)}\\\\$

which is the same as solving

$\tan(2x) = \frac{2w}{1-w^2}\\\\$

where w = tan(x)

Plug in tan(2x) = 24/7 and solve for w to get w = -4/3 or w = 3/4

So either tan(x) = -4/3 or tan(x) = 3/4.

If we were to numerically solve the original equation for x, then we'd get roughly x = 2.21; then notice how tan(2.21) = -1.345 approximately when your calculator is in radian mode.

Since tan(x) < 0 in this case, we go for tan(x) = -4/3

8 0

3 years ago

The five numbers summary for a data set is shown below. What is the range of the data set? 3, 7, 11, 14, 16

scoundrel [369]

Answer:

Step-by-step explanation:

The range of a set of data is the difference between the highest and lowest values in the set.

So, in order to find the range, you first order the data from least to greatest. Which it is already.

3, 7, 11, 14, 16

Then subtract the smallest value from the largest value in the set.

16 - 3 = 13

Hope this helps you out! : )

3 0

3 years ago

Y=2x-4<br> What are the five ordered pairs

yarga [219]

Answer:

y= 2x+9

y=2x-1

y=2x-13

y=2x-2

y=2x+7

6 0

2 years ago