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2 years ago

15

After four rounds, 74 teams are eliminated from a robotics competition. There are 18 teams remaining. Write and solve an equatio

n to find the number of teams t that started the competition.

1 answer:

Mariulka [41]2 years ago

4 0

It is 92 .............

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The following 5 questions are based on this information: An economist claims that average weekly food expenditure of households

liq [111]

Answer:

Null hypothesis: $\mu_{1}-\mu_{0}\leq 0$

Alternative hypothesis: $\mu_{1}-\mu_{2}>0$

$SE=\sqrt{\frac{12.5^2}{35}+\frac{9.25^2}{30}}=2.705$

b) 2.70

$t=\frac{(164-159)-0}{\sqrt{\frac{12.5^2}{35}+\frac{9.25^2}{30}}}=1.850$

b. 1.85

$p_v =P(Z>1.85)=0.032$

b. 0.03

a. We can reject H(0) in favor of H(a)

Step-by-step explanation:

Data given and notation

$\bar X_{1}=164$ represent the mean for the sample 1

$\bar X_{2}=159$ represent the mean for the sample 2

$\sigma_{1}=12.5$ represent the population standard deviation for the sample 1

$s_{2}=9.25$ represent the population standard deviation for the sample B2

$n_{1}=35$ sample size selected 1

$n_{2}=30$ sample size selected 2

$\alpha=0.05$ represent the significance level for the hypothesis test.

t would represent the statistic (variable of interest)

$p_v$ represent the p value for the test (variable of interest)

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the expenditure of households in City 1 is more than that of households in City 2, the system of hypothesis would be:

Null hypothesis: $\mu_{1}-\mu_{0}\leq 0$

Alternative hypothesis: $\mu_{1}-\mu_{2}>0$

We know the population deviations, so for this case is better apply a z test to compare means, and the statistic is given by:

$z=\frac{(\bar X_{1}-\bar X_{2})-0}{\sqrt{\frac{\sigma^2_{1}}{n_{1}}+\frac{\sigma^2_{2}}{n_{2}}}}$ (1)

t-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".

Standard error

The standard error on this case is given by:

$SE=\sqrt{\frac{s^2_{1}}{n_{1}}+\frac{s^2_{2}}{n_{2}}}$

Replacing the values that we have we got:

$SE=\sqrt{\frac{12.5^2}{35}+\frac{9.25^2}{30}}=2.705$

b. 2.70

Calculate the statistic

We can replace in formula (1) the info given like this:

$t=\frac{(164-159)-0}{\sqrt{\frac{12.5^2}{35}+\frac{9.25^2}{30}}}=1.850$

P-value

Since is a one side right tailed test the p value would be:

$p_v =P(Z>1.85)=0.032$

b. 0.03

Conclusion

If we compare the p value and the significance level given $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis.

a. We can reject H(0) in favor of H(a)

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2 years ago

Using the distance formulas, find the equation of a parabola with a focus of (3, 4) and a directrix of y = −2.

Charra [1.4K]

Try using a site like Khan Academy to get a solution

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2 years ago

50 points! Someone actually help instead of putting random answers! Random answers will be reported

In-s [12.5K]

<em>If</em><em> </em><em>you</em><em> </em><em>only</em><em> </em><em>want</em><em> </em><em>to</em><em> </em><em>see</em><em> </em><em>the</em><em> </em><em>way</em><em> </em><em>i do</em><em> </em><em>it</em><em> </em><em>to</em><em> </em><em>get</em><em> </em><em>the</em><em> </em><em>answer</em><em> </em><em>without</em><em> </em><em>seeing</em><em> </em><em>my</em><em> </em><em>explanation</em><em> </em><em>ignore</em><em> </em><em>sentences</em><em> </em><em>with</em><em> </em><em>symbol</em><em> </em><em>'</em><em>#</em><em>'</em>

<h2>Answer</h2>

•Pic on the left

x = 8.36

y = 140.18°

• Pic on the right

x = 110°

<h2>Way to do</h2>

• This one for the pic on the left

#Since the total degree of a triangle is 180° and one of the side known 90° (L) so the rest must be 90° (180° - 90° = 90°)

#known that the other side of triangle degree is (5x - 2)° and 6x° so... u can find the x! :D

90 = (5x - 2) + 6x

90 = 11x - 2

90 + 2 = 11x

92 = 11x

x = 92 : 11

x = 8.36 (2 decimal places)

#Now you know the x, you can now find the degree

#degree of (5x - 2)

5x - 2 =

5(8.36) - 2 =

41.81 - 2 = 39.81

#Since the y° is in the other side of the line of degre 39.81°, you can find it by minus it with 180° (straight line with no degree is 180°)

180° - 39.81° = 140.18

•This one for the pic on the right

#Lol this one is easy. I already told you before that the straight line degree is 180° and you can find one of the side if you know one of the degree side, so you can find it.

# Also as i said before, total triangle degree is 360°

#Find the degree of the other side of x° (only can find the degree of other side x because its inside the triangle)

Degree = 180° - 80° - 30° = 70°

#Now you can get x

x = 180° - 70° = 110°

<h2>For moderators that see this</h2>

#Moderators please don't be mean, dont delete my answers just for approval from your senior or just to get the biggest moderation daily rank. This answer is long, how can you just instanly delete it? :(

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2 years ago

Read 2 more answers

Write 42/100 in standard form as a decimal

iragen [17]

Answer:

0.42

Step-by-step explanation:

divide 100÷42 then the answer is 0.42

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2 years ago

If the coordinates of point A are (-3, 2) and the coordinates of point B are (7, 6), the x-intercept of is . Point lies on .

solmaris [256]

You would move five down and eight to the right, it depends how how the grid is

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3 years ago