Use the following situation to answer the questions for this quiz:

Simplify: {(-8)^-4 ÷ 2^-8}^2

Aleksandr-060686 [28]

Answer:

ok so first we have to do whats in the brackets then we have to do to exponits so first

(-0.00024414062divided by 0.00390625)^2

-0.06249999872^2

-0.00390624984

Hope This Helps!!!

8 0

2 years ago

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In a statistics class, the standard deviation of the heights of all students was 3.8 inches. The standard deviation of the heig

goblinko [34]

Answer:

The reason why standard deviation of the entire class is greater than standard deviation of males and females considered separately, is that mean values for males and females are different from each other.

Step-by-step explanation:

The concept of mean is well represented by the following formula

mean = $\frac{(x1 + x2 + x3 + ..... + xn)}{N}$ , where x1, x2, xn are the observations and N is the number of observations (population).

Standard deviation represents the distance between each observation and the mean of the population (all observations). The formula for this parameter is:

Standard deviation =√[((x1 - x)² + (x2-x)² + ....+ (xn-x)²)/N-1], where x1, x2,..., xn are the observations and x is the mean value.

In this case you have that each height registered is an observation and the number of observations represents the N value. As you can see if the mean for males is different from that of females their standard deviation will be different too. Usually males have heigths greater than that of females (1.77 vs 1.64, in USA for example), and heights inside each group will be more similar than between groups. Then, when you mix all observation there will be an increase in standard deviation, because you are mixing very different heigths

4 0

3 years ago

(y+1/x)^(x+y)*(x-1/y)^(x+y)÷{(x^2-1/y^2)^x*(y^2-1/x^2)^y}

Yuki888 [10]

Answer:

is it right question or not tell me and I will solve it

6 0

3 years ago

Read 2 more answers

Ten engineering schools in the United States were surveyed. The sample contained 250 electrical engineers, 80 being women; 175 c

steposvetlana [31]

Answer:

There is a significant difference between the two proportions.

Step-by-step explanation:

The (1 - α)% confidence interval for difference between population proportions is:

$CI=(\hat p_{1}-\hat p_{2})\pm z_{\alpha/2}\times\sqrt{\frac{\hat p_{1}(1-\hat p_{1})}{n_{1}}+\frac{\hat p_{2}(1-\hat p_{2})}{n_{2}}}$

Compute the sample proportions as follows:

$\hat p_{1}=\frac{80}{250}=0.32\\\\\hat p_{2}=\frac{40}{175}=0.23$

The critical value of z for 90% confidence interval is:

$z_{0.10/2}=z_{0.05}=1.645$

Compute a 90% confidence interval for the difference between the proportions of women in these two fields of engineering as follows:

$CI=(\hat p_{1}-\hat p_{2})\pm z_{\alpha/2}\times\sqrt{\frac{\hat p_{1}(1-\hat p_{1})}{n_{1}}+\frac{\hat p_{2}(1-\hat p_{2})}{n_{2}}}$

$=(0.32-0.23)\pm 1.645\times\sqrt{\frac{0.32(1-0.32)}{250}+\frac{0.23(1-0.23)}{175}}\\\\=0.09\pm 0.0714\\\\=(0.0186, 0.1614)\\\\\approx (0.02, 0.16)$

There will be no difference between the two proportions if the 90% confidence interval consists of 0.

But the 90% confidence interval does not consists of 0.

Thus, there is a significant difference between the two proportions.

4 0

3 years ago

Find the area of the shapes below. Make sure to label your answers with units.

Anvisha [2.4K]

Triangle: 13.3 km Why: the formula is 1/2 base x height.
Square: 57.4 Why: 7x8.2 which equals 57.4

3 0

2 years ago