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3 years ago

What happens to the surface area of a rectangular prism when each of the dimensions is doubled? (1 point) i?

1 answer:

5 0

The surface area will be 4 times the original size. Here is why: You are doubling each dimension, and area is a 2 dimensional measurement. Because of this whatever you are doing to the length of the side will happen 2 times. In this case it would be x2 x2 which equals 4. You can provide evident by using a cube. The surface area of a cube with side lengths of 1 would be 1 x 6=6 square inches. If you double the side length, it would be 4 x 6= 24 square inches.

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kakasveta [241]

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What number has a prime factorization of 2x 5^2

andrew11 [14]

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2 years ago

2. The National Safety Council routinely analyzes the benefit of seat belt use on driver safety. Their data showed that among 28

JulijaS [17]

Answer:

We conclude that there is difference in the proportion of deaths between the 2 groups.

Step-by-step explanation:

We are given that among 2823 drivers not wearing seat belts, 31 died as a result of injuries, and among 7765 drivers wearing seat belts 16 were killed.

Let $p_1$ = proportion of deaths when drivers were not wearing seat belts.

$p_2$ = proportion of deaths when drivers were wearing seat belts.

So, Null Hypothesis, $H_0$ : $p_1=p_2$ {means that there is no difference in the proportion of deaths between the 2 groups}

Alternate Hypothesis, $H_A$ : $p_1\neq p_2$ {means that there is difference in the proportion of deaths between the 2 groups}

The test statistics that would be used here Two-sample z test for proportions;

T.S. = $\frac{(\hat p_1-\hat p_2)-(p_1-p_2)}{\sqrt{\frac{\hat p_1(1-\hat p_1)}{n_1}+\frac{\hat p_2(1-\hat p_2)}{n_2} } }$ ~ N(0,1)

where, $\hat p_1$ = sample proportion of deaths when drivers were not wearing seat belts = $\frac{31}{2823}$ = 0.011

$\hat p_2$ = sample proportion of deaths when drivers were wearing seat belts = $\frac{16}{7765}$ = 0.002

$n_1$ = sample of drivers not wearing seat belts = 2823

$n_2$ = sample of drivers wearing seat belts = 7765

So, the test statistics = $\frac{(0.011-0.002)-(0)}{\sqrt{\frac{0.011(1-0.011)}{2823}+\frac{0.002(1-0.002)}{7765} } }$

= 4.438

The value of z test statistics is 4.438.

Now, at 5% significance level the z table gives critical values of -1.96 and 1.96 for two-tailed test.

Since our test statistic doesn't lie within the range of critical values of z, so we have sufficient evidence to reject our null hypothesis as it will fall in the rejection region due to which we reject our null hypothesis.

Therefore, we conclude that there is difference in the proportion of deaths between the 2 groups.

Also, Margin of error (E) = $1.96 \times \sqrt{\frac{\hat p_1(1-\hat p_1)}{n_1}+\frac{\hat p_2(1-\hat p_2)}{n_2} }$

= $1.96 \times \sqrt{\frac{0.011(1-0.011)}{2823}+\frac{0.002(1-0.002)}{7765} }$

= 0.00397

5 0

3 years ago

Xin Used 20 yards of fencing to build the walls of a square a chicken coop. Used 20 yards of fencing to build the walls of a squ

Gnoma [55]

Answer:

Equation: $20=4x$ or $x=\frac{20}{4}$

Solution: $x=5$

Step-by-step explanation:

The formula that is used to calculate the perimeter of a square is:

$P=4s$

Where "s" is the side lenght the square.

Knowing that Xin used 20 yards of fencing to build the walls of a square chicken coop (in which the lenght in yards of each wall is represented with "x"), you can identify that:

$P=20\\\\s=x$

Then, you can susbtitute values into the formula $P=4s$ :

$20=4x$

Finally, you must solve for "x" in order to find its value.

This is:

$\frac{20}{4}=x\\\\x=5$

6 0

3 years ago