.

A box is dragged 16 m across a level floor by a 25-N force at an angle of 45° to the floor. It is then dragged by

Nuetrik [128]

<u>solution</u>

W=f×d×cos theta

=25N×16m×cos 45°

=400Nm×cos 45°

=282.84J

W=f×d×cos theta

=25N×7m×cos 10°

=175Nm×cos10°

=172.34J

Total workdone=282.84J+172.34J=455.18J

7 0

3 years ago

Identify the x- intercepts of the graphed function.

yarga [219]

The x-intercepts are indeed -1 and 1.

The increasing intervals are listed as (-1, 0) u (1, infinity) not because -1 and 1 are not included points of the function, but because the function is not differentiable in those points, so you can't tell whether the function is increasing or decreasing there.

3 0

3 years ago

Twice the difference of a number and

Cerrena [4.2K]

2(w-8) = 9. Hope it helps!

4 0

3 years ago

My brother wants to estimate the proportion of Canadians who own their house.What sample size should be obtained if he wants the

AVprozaik [17]

Answer:

a) $n=\frac{0.675(1-0.675)}{(\frac{0.02}{1.64})^2}=1475.07$

And rounded up we have that n=1476

b) $n=\frac{0.5(1-0.5)}{(\frac{0.02}{1.64})^2}=1681$

And rounded up we have that n=1681

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".

The population proportion have the following distribution

$p \sim N(p,\sqrt{\frac{\hat p(1-\hat p)}{n}})$

The margin of error for the proportion interval is given by this formula:

$ME=z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$ (a)

If solve n from equation (a) we got:

$n=\frac{\hat p (1-\hat p)}{(\frac{ME}{z})^2}$ (b)

Part a

In order to find the critical value we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. Since our interval is at 90% of confidence, our significance level would be given by $\alpha=1-0.9=0.1$ and $\alpha/2 =0.05$ . And the critical value would be given by:

$z_{\alpha/2}=\pm 1.64$

The margin of error for the proportion interval is given by this formula:

$ME=z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$ (a)

And on this case we have that $ME =\pm 0.02$ and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=\frac{\hat p (1-\hat p)}{(\frac{ME}{z})^2}$ (b)

And replacing into equation (b) the values from part a we got:

$n=\frac{0.675(1-0.675)}{(\frac{0.02}{1.64})^2}=1475.07$

And rounded up we have that n=1476

Part b

For this case since we don't have a prior estimate we can use $\hat p =0.5$

$n=\frac{0.5(1-0.5)}{(\frac{0.02}{1.64})^2}=1681$

And rounded up we have that n=1681

8 0

3 years ago

A pasta meal costs $8.95 at a local restaurant the cost to make a copycat version of the pasta meal at home is only $4.75 comple

coldgirl [10]

The absolute and relative cost difference in the restaurant and copycat meal are :

Copycat meal is $4.20 less than restaurant meal

Restaurant meal cost 1.88 times as much as copycat meal

Copycat meal is 53% of the cost of restaurant meal

Cost of restaurant meal = $8.95

Cost of copycat version = $4.75

1.)

Difference in cost of meal for both version :

Cost of restaurant meal - Cost of copycat version

($8.95 - $4.75) = $4.20.

The copycat meal is $4.20 less than the restaurant meal

2.)

Cost of restaurant meal ÷ Cost of copycat version

($8.95 ÷ $4.75) = 1.884 = 1.88(2 decimal places)

The restaurant meal cost 1.88 times as much as the copycat meal

3.)

Percentage = (8.95 - 4.75) × 100% = 53.07% = 53%(nearest whole number)

The copycat meal is 53% of the cost of restaurant meal

Therefore, the relative and absolute cost difference are $4.20, 1.88 times and 53%

Learn more :brainly.com/question/13218948

7 0

2 years ago