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3 years ago

!!MATH GENIUSES HELP ME!!

Mathematics

1 answer:

seraphim [82]3 years ago

8 0

Answer:

Step-by-step explanation:

Let x be Bill’s scores.

Let y be Theo’s scores.

x + y = 90

x² = y

Solve for x in the second equation.

x = √y

Put x as √y in the first equation and solve for y.

√y + y = 90

√y = 90 - y

y = (90 - y)²

y = - y² - 180y - 8100

0 = -y² - 181y - 8100

0 = (-y+81)(y-100)

-y+81=0

y = 81

y - 100 = 0

y = 100

100 does not work if we plug in to check, so y is 81.

y = 81

Put y as 81 in the first equation and solve for x.

x + 81 = 90

x = 9

Bill scored 9 goals and Theo scored 81.

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The distance between two cities on a map is 3.5 centimeters. The map uses a scale in which 1 centimeter represents 20 kilometers

zhenek [66]

1 cm = 20 km

so 3.5 cm would equal : 3.5 * 20 = 70 km <==

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3 years ago

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Researchers fed mice a specific amount of Dieldrin, a poisonous pesticide, and studied their nervous systems to find out why Die

Elodia [21]

Answer:

Step-by-step explanation:

Part A

Mean = (2.2 + 2.4 + 2.5 + 2.5 + 2.6 + 2.7)/6 = 2.48

Standard deviation = √(summation(x - mean)²/n

n = 6

Summation(x - mean)² = (2.2 - 2.48)^2 + (2.4 - 2.48)^2 + (2.5 - 2.48)^2 + (2.5 - 2.48)^2 + (2.6 - 2.48)^2 + (2.7 - 2.48)^2 = 0.1484

Standard deviation = √(0.1484/6

s = 0.16

Standard error = s/√n = 0.16/√6 = 0.065

Part B

Confidence interval is written as sample mean ± margin of error

Margin of error = z × s/√n

Since sample size is small and population standard deviation is unknown, z for 98% confidence level would be the t score from the student t distribution table. Degree of freedom = n - 1 = 6 - 1 = 5

Therefore, z = 3.365

Margin of error = 3.365 × 0.16/√6 = 0.22

Confidence interval is 2.48 ± 0.22

Part C

We would set up the hypothesis test. This is a test of a single population mean since we are dealing with mean

For the null hypothesis,

H0: µ = 2.3

For the alternative hypothesis,

H1: µ > 2.3

This is a right tailed test

Since the number of samples is small and no population standard deviation is given, the distribution is a student's t.

Since n = 6

Degrees of freedom, df = n - 1 = 6 - 1 = 5

t = (x - µ)/(s/√n)

Where

x = sample mean = 2.48

µ = population mean = 2.3

s = samples standard deviation = 0.16

t = (2.48 - 2.3)/(0.16/√6) = 2.76

We would determine the p value using the t test calculator. It becomes

p = 0.02

Assuming significance level, alpha = 0.05.

Since alpha, 0.05 > than the p value, 0.02, then we would reject the null hypothesis. Therefore, At a 5% level of significance, the sample data showed significant evidence that the mean absolute refractory period for all mice when subjected to the same treatment increased.

6 0

3 years ago

Making a career decision is simple, and it's not necessary to use a process. true or fralse

tino4ka555 [31]

Making a career decision is simple but important task. And a proper process needs to be followed. By a process, we can say choosing the subject interest, finding the career options in your interest area, figuring out the college and the cost of education. And most important working with patience and honesty is the fundamental to reach a zenith in your career.

8 0

3 years ago

Brianna is going to a carnival that has games and rides. Each game costs $1.25 and each ride costs $3.75. Brianna spent $18.75 a

maxonik [38]

Answer:

6 games and 3 rides

Step-by-step explanation:

Let the number of games Brianna played be x,

and the number of rides she went on be y.

Total cost for games= 1.25x

Total cost for rides= 3.75y

Since number of games is twice the number of rides,

x= 2y -----(1)

Total costs= cost of games +cost of rides

$18.75= 1.25x +3.75y$

Multiply the whole equation by 4 to remove the decimals:

$75= 5x +15y$

Simplify by dividing the whole equation by 5:

$15 = x + 3y$

Label the equation:

x +3y= 15 -----(2)

Although we can solve these 2 equations by substitution, since the question requires us to graphically solve, we have to graph 2 linear lines.

I will choose 3 points to plot on the graph for each equation:

x= 2y -----(1)

$\begin{tabular}{|c|c|c|c|} \cline{1-4}x & 2(1) = 2&2(2) = 4&2(3) = 6\\ \cline{1-4}y & 1 &2&3\\ \cline{1-4}\end{tabular}$

x +3y= 15 -----(2)

x= -3y +15

$\begin{tabular}{|c|c|c|c|} \cline{1-4}x & -3(1)+15= 12& -3(2)+15= 9& -3(3)+15= 6\\ \cline{1-4}y & 1 &2&3\\ \cline{1-4}\end{tabular}$

Let's plot these points on a graph paper. Then, join them with a straight line for each straight line graph. Please see the attached picture for the graph.

From (1): y= ½x

From (2): 3y= 15 -x

y= 5 -⅓x

From the graph, the solution of the equation is (6,3). The solution is the point on the graph in which the 2 lines intersect.

x- coordinate: 6

y- coordinate: 3

Thus, Brianna played 6 games and went on 3 rides.

8 0

3 years ago

Read 2 more answers

2. My bank account contains pesos 3021 and make monthly withdrawals of pesos 78 for 12 months. What is my new bank balance.

Agata [3.3K]

Answer:

ok I will try solve your problem. good luck

Step-by-step explanation:

a. known: Bank balances : 3021 pesos

monthly withdrawals: 78 pesos

months of withdrawal: 12 months

b. asked: new bank balance?

c. equation: New bank balance= bank balance - ( monthly withdrawals X months of withdrawal)

d. New bank balance: 3021- (78x12)

= 3021 - 936

= 2085 pesos

e. my new bank balance is 2085 pesos.

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1 year ago