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3 years ago

Plz help me with this question involving ratios.Show your work.(It is 1 question)

Mathematics

1 answer:

Ierofanga [76]3 years ago

7 0

You divide 5.625 by 125 and that's x and for y you multiply 420 to 1,875

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Evaluate.<br> 418!<br> 2!7!<br> plzzzz helpppp

zavuch27 [327]

Answer:

whatttttt6 whattttt whattt

7 0

3 years ago

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PLEASE HELP ASAP!!!!

musickatia [10]

Let us model this problem with a polynomial function.

Let x = day number (1,2,3,4, ...)
Let y = number of creatures colled on day x.

Because we have 5 data points, we shall use a 4th order polynomial of the form
y = a₁x⁴ + a₂x³ + a₃x² + a₄x + a₅

Substitute x=1,2, ..., 5 into y(x) to obtain the matrix equation
| 1 1 1 1 1 | | a₁ | | 42 |
| 2⁴ 2³ 2² 2¹ 2⁰ | | a₂ | | 26 |
| 3⁴ 3³ 3² 3¹ 3⁰ | | a₃ | = | 61 |
| 4⁴ 4³ 4² 4¹ 4⁰ | | a₄ | | 65 |
| 5⁴ 5³ 5² 5¹ 5⁰ | | a₅ | | 56 |

When this matrix equation is solved in the calculator, we obtain
a₁ = 4.1667
a₂ = -55.3333
a₃ = 253.3333
a₄ = -451.1667
a₅ = 291.0000

Test the solution.
y(1) = 42
y(2) = 26
y(3) = 61
y(4) = 65
y(5) = 56

The average for 5 days is (42+26+61+65+56)/5 = 50.
If Kathy collected 53 creatures instead of 56 on day 5, the average becomes
(42+26+61+65+53)/5 = 49.4.

Now predict values for days 5,7,8.
y(6) = 152
y(7) = 571
y(8) = 1631

3 0

3 years ago

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Select the correct answer.<br> What is the value of x?

aksik [14]

Answer:

7.5

Step-by-step explanation:

8 0

2 years ago

.11 A machine produces metal pieces that are cylindrical in shape. A sample of pieces is taken, and the diameters are found to b

Troyanec [42]

Answer:

The 99% confidence interval for the mean diameter of pieces from this machine is between 0.93 and 1.07.

Step-by-step explanation:

Sample mean:

Sum of all values divided by the number of values. So

$M = \frac{1.01+0.97+1.03+1.04+0.99+0.98+0.99+1.01+1.03}{9} = 1$

Sample standard deviation:

Square root of the sum of the differences between each value and the mean, divided by the 1 less than the sample size. So

$s = \sqrt{\frac{(1.01-1)^2+(0.97-1)^2+(1.03-1)^2+(1.04-1)^2+(0.99-1)^2+(0.98-1)^2+(0.99-1)^2+(1.01-1)^2+(1.03-1)^2}{8}} = 0.0657$

Confidence interval:

We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 9 - 1 = 8

99% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 8 degrees of freedom(y-axis) and a confidence level of $1 - \frac{1 - 0.99}{2} = 0.995$ . So we have T = 3.355

The margin of error is:

$M = T\frac{s}{\sqrt{n}} = 3.355\frac{0.0657}{\sqrt{9}} = 0.07$

In which s is the standard deviation of the sample and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 1 - 0.07 = 0.93

The upper end of the interval is the sample mean added to M. So it is 1 + 0.07 = 1.07

The 99% confidence interval for the mean diameter of pieces from this machine is between 0.93 and 1.07.

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3 years ago

Mrs. Powell has $800 invested in stocks and $500 invested in a Certificate of Deposit. The CD has an interest rate twice as grea

Mashutka [201]

Let's use the variable "r" to represent the investment rate of the stocks:
2r(500) + r(800) = 45
1000r + 800r = 45
1800r = 45
r = 0.025
2r = 0.05
The $500 is invested at 5%

7 0

3 years ago

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