if a euro equals 1.2 american dollars write an expression which estimates the number of dollars in x euros

A fence 6 ft high runs parallel to the wall of a house at a distance of 5 ft. Find the length of the shortest ladder that extend

Anettt [7]

Answer:

L = 15.53 ft

Step-by-step explanation:

using diagram which is attached below

now, using Pythagoras theorem

L² = b² + (5 + x)²...............(1)

using similarity of triangle

$\dfrac{x}{6}=\dfrac{5+x}{b}$

$b=\dfrac{5+x}{x}6$

from equation (1)

$L^2 = (\dfrac{5+x}{x}6)^2 + (5 + x)^2$

$= (5+x)^2(1+\dfrac{36}{x^2})$

$\frac{\mathrm{d} L^2}{\mathrm{d} x}= 2(5+x)(1+\dfrac{36}{x^2})+(5+x)^2(\dfrac{-2\times 36}{x^3})$

$\frac{\mathrm{d} L^2}{\mathrm{d} x}= (5+x)(2-\dfrac{72\times 5}{x^3})$

for maxima or minima

$\frac{\mathrm{d} L^2}{\mathrm{d} x}=0$

x = -5 and x = ∛190 = 5.74

on second derivative 5.74 is the value which comes out to be minimal value which is the distance between the fence and ladder

now,

L² = 241.38

L = 15.53 ft

7 0

3 years ago

A random sample of 180 microbiology students were asked how many science classes he or she was enrolled in August 1990. The resu

frutty [35]

Answer:

$z=\frac{1.83-1.94}{\sqrt{\frac{1.48^2}{180}+\frac{1.62^2}{180}}}}=-0.673$

$p_v =2*P(z$

Comparing the p value with the significance level given $\alpha=0.05$ we see that $p_v>\alpha$ so we can conclude that we FAIL to reject the null hypothesis, and a would NOT be a significant difference in the two means

Step-by-step explanation:

Data given and notation

$\bar X_{1}=1.83$ represent the mean in 1990

$\bar X_{2}=1.94$ represent the mean for 2005

$s_{1}=1.48$ represent the sample deviation for 1990

$s_{2}=1.62$ represent the sample standard deviation for 2005

$n_{1}=180$ sample size for 1990

$n_{2}=180$ sample size for 2005

t would represent the statistic (variable of interest)

$\alpha=0.05$ significance level provided

Develop the null and alternative hypotheses for this study?

We need to conduct a hypothesis in order to check if the means for the two groups are different, the system of hypothesis would be:

Null hypothesis: $\mu_{1}=\mu_{2}$

Alternative hypothesis: $\mu_{1} \neq \mu_{2}$

Since we don't know the population deviations for each group, for this case is better apply a t test to compare means, and the statistic is given by:

$z=\frac{\bar X_{1}-\bar X_{2}}{\sqrt{\frac{s^2_{1}}{n_{1}}+\frac{s^2_{2}}{n_{2}}}}$ (1)

z-test: Is used to compare group means. Is one of the most common tests and is used to determine whether the means of two groups are equal to each other.

Calculate the value of the test statistic for this hypothesis testing.

Since we have all the values we can replace in formula (1) like this:

$z=\frac{1.83-1.94}{\sqrt{\frac{1.48^2}{180}+\frac{1.62^2}{180}}}}=-0.673$

What is the p-value for this hypothesis test?

Since is a bilateral test the p value would be:

$p_v =2*P(z$

Based on the p-value, what is your conclusion?

Comparing the p value with the significance level given $\alpha=0.05$ we see that $p_v>\alpha$ so we can conclude that we FAIL to reject the null hypothesis, and a would NOT be a significant difference in the two means

8 0

4 years ago

Which is a simplified form of the expression 4(2x+3) - 3(x + 4)?

Kazeer [188]

Answer:

5x

Step-by-step explanation:

4(2x+3)-3(x+4)

4(2x) + 4(3) - 3(x) - 3(4)

8x + 12 - 3x - 12

8x - 3x + 12 - 12

5x

8 0

3 years ago

20 POINTS! You are planning to use a ceramic tile design in your new bathroom. The tiles are equilateral triangles. You decide t

Margarita [4]

Answer:

210.33 cm^2

Step-by-step explanation:

We know that 6 equilateral triangles makes one hexagon.

Also, an equilateral triangle has all its sides equal.

If the tile of each side of the triangular tile measure 9 cm, then the height of the triangular tiles can be gotten using Pythagoras's Theorem.

The triangle formed by each tile can be split along its height, into two right angle triangles with base (adjacent) 4.5 cm and slant side (hypotenuse) of 9 cm. The height (opposite) is calculated as,

From Pythagoras's theorem,

$hyp^{2} = adj^{2} + opp^{2}$