Logan trades 50 pennies for nickels. He gets a nickel for each group of 5 pennies.

shanti wrote the predicted values for a data set using the line of best fit y = 2.55x – 3.15. she computed two of the residual v

Delvig [45]

<span>The question asks us to determine the values for a and b in the linear equation. Linear equation in the slope-intercept form is : y = a x + b. This equation is: y = 2.25 x - 3.15. The slope: a = 2.25 and the y-intercept is: b = -3.15. Answer: a = 2.25 and b = - 3.15.</span>

8 0

2 years ago

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Lyn invested $7,000 into a investment paying 3% interest, compounded semi-annually, twice a year. After five years, how much wou

gayaneshka [121]

Answer:

Option B.) $8,123.79

Step-by-step explanation:

we know that

The compound interest formula is equal to

$A=P(1+\frac{r}{n})^{nt}$

where

A is the Final Investment Value

P is the Principal amount of money to be invested

r is the rate of interest in decimal

t is Number of Time Periods

n is the number of times interest is compounded per year

in this problem we have

$t=5\ years\\ P=\$7,000\\ r=0.03\\n=2$

substitute in the formula above

$A=\$7,000(1+\frac{0.03}{2})^{2*5}$

$A=\$7,000(1.015)^{10}=\$8,123.79$

3 0

2 years ago

The heights of a random sample of 50 college students showed a mean of 174.5 centimeters and a standard deviation of 6.9 centime

Minchanka [31]

Answer:

Step-by-step explanation:

Hello!

For me, the first step to any statistics exercise is to determine what is the variable of interest and it's distribution.

In this example the variable is:

X: height of a college student. (cm)

There is no information about the variable distribution. To estimate the population mean you need a variable with at least a normal distribution since the mean is a parameter of it.

The option you have is to apply the Central Limit Theorem.

The central limit theorem states that if you have a population with probability function f(X;μ,δ²) from which a random sample of size n is selected. Then the distribution of the sample mean tends to the normal distribution with mean μ and variance δ²/n when the sample size tends to infinity.

As a rule, a sample of size greater than or equal to 30 is considered sufficient to apply the theorem and use the approximation.

The sample size in this exercise is n=50 so we can apply the theorem and approximate the distribution of the sample mean to normal:

X[bar]~~N(μ;σ2/n)

Thanks to this approximation you can use an approximation of the standard normal to calculate the confidence interval:

98% CI

1 - α: 0.98

⇒α: 0.02

α/2: 0.01

$Z_{1-\alpha /2}= Z_{1-0.01}= Z_{0.99} =2.334$

X[bar] ± $Z_{1-\alpha /2} * \frac{S}{\sqrt{n} }$

174.5 ± $2.334* \frac{6.9}{\sqrt{50} }$

[172.22; 176.78]

With a confidence level of 98%, you'd expect that the true average height of college students will be contained in the interval [172.22; 176.78].

I hope it helps!

4 0

2 years ago

The graph of a sinusoidal function has a maximum point at (0,5)(0,5)left parenthesis, 0, comma, 5, right parenthesis and then ha

Ksivusya [100]

Answer:

sinusoidal functions have the standard form of Asin(Bx - C) + D

Where A is the amplitude, 2pi/B gives us our period, C gives us our horizontal shifts in the opposite direction of the sign (because it's inside the parenthesis), and D gives us our vertical shifts in the same direction as the sign of D (positive or negative).

The easiest part is assigning the amplitude which is 3 as stated in the problem. This means that all of the max/mins of the graph will be multiplied by a factor of 3. However, this could be a positive or negative 3 depending on other info in the problem. We'll come back to this in a second.

We know 2pi/B = 8 in our problem. Solving for B gives us B = pi/4.

Now we need to find the corresponding maximum and minimums for a sin/cos function with a period of 8 by taking x values 0, pi/2, pi, 3pi/2, and 2pi (these are all values where normal sin/cos functions are either at their max/min or zero) and then divide each by pi/4. This will give us our new max/mins for a function with period 8. These values are 0, 2, 4, 6, and 8.

Since 2 is a minimum, then we know that there are no horizontal shifts. So C = o

Now we need to figure out if this is a sin or cos graph. A normal cos graph has a value of 0 at x = pi/2 which corresponds x = 2 in our problem. Your problem says that x = 2 will give us a minimum value so this tells us that our function must be a sin graph, not a cos graph. However, a sin graph has a maximum at 2 (which is pi/2 in a normal sin graph) while your problem calls for a minimum. This means that the amplitude we found earlier of 3 must actually be a -3 (I told you we'd get back to this!). The negative sign flips all of the maximums to minimums and vice versa of the sinusoidal graph.

Ok, let's put together what we know so far. A = -3, B = pi/4, and C = 0. So f(x) = -3sin((pi/4)x) + d

......But what about D?

Well, your problem says that one minimum of the graph is (2,1). In a graph without vertical shifts, we would expect the minimum to be at (2,-3). The difference between -3 and 1 is 4. This means in order to get from -3 to 1 we have to shift upwards of 4 units. In other words, D = 4.

Answer: -3sin((pi/4)x) + 4

Step-by-step explanation:

4 0

2 years ago

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A regular hexagon rotates counterclockwise around its center. It turns through angles greater than 0° and less or equal to 360°.

Sonja [21]

there are 6 sides to a hexagon

360/6 = 60 degrees

so it will map onto itself at 60, 120, 180, 240, 300 & 360

there are 6 different angles

6 0

2 years ago