Suppose there are 8 boys and 7 girls in a classroom. If one student is chosen at random to run a errand. What is the probability that the student will be a girl?

Answer:

150a

Step-by-step explanation:

a. The probability of all girls in a family with four children is 1/16 or 0.0625.

b. The probability of all girls given there is at least one girl is 1/15 or 0.0667.

c. The probability of having at least one boy and one girl in a family with four children is 15/16 or 0.9375.

a. To calculate the probability of all girls, we need to consider the possible outcomes of each child being a girl. Since each child has an independent probability of being a girl or a boy, the probability of all girls is (1/2) * (1/2) * (1/2) * (1/2) = 1/16 or 0.0625.

b. Given that there is at least one girl, we have three remaining children. The probability of all girls among the three remaining children is (1/2) * (1/2) * (1/2) = 1/8. Therefore, the probability of all girls given there is at least one girl is 1/8 divided by the probability of having at least one girl, which is 1 - (1/2)⁴ = 15/16, resulting in a probability of 1/15 or approximately 0.0667.

c. The probability of having at least one boy and one girl can be calculated by subtracting the probability of having all boys from the total probability space. The probability of having all boys is (1/2)⁴ = 1/16. Therefore, the probability of having at least one boy and one girl is 1 - 1/16 = 15/16 or approximately 0.9375. This probability accounts for all possible combinations of boys and girls in a family with four children, excluding the scenario of having all boys.

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A. Does mean blood pressure differ for three different age groups?

This is a research question that could be addressed using a one-way analysis of variance.

A one-way analysis of variance (ANOVA) is a statistical test used to determine whether there are any significant differences between the means of three or more groups. In the given research question, we are interested in examining whether the mean blood pressure differs across three different age groups.

To address this question using a one-way ANOVA, we would collect blood pressure measurements from individuals belonging to three different age groups. We would then calculate the mean blood pressure for each group and compare these means statistically. The one-way ANOVA test would allow us to determine if there is enough evidence to suggest that the mean blood pressure differs significantly between the age groups.

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By using iteration, we can guess the explicit formula for the given sequence. It is found that the sequence follows a quadratic pattern, and the explicit formula is dx = 3([tex]2^{k-1}[/tex]) + 3[tex]k^2[/tex] - 6k + 3.

Let's start by analyzing the given sequence: dx = 2dx-1 + 3[tex]k^2[/tex]. We are given that d1 = 3. We can use this initial value to find d2, d3, and so on.

Substituting k = 2 into the given equation, we get d2 = 2d1 + 3([tex]2^2[/tex]) = 2(3) + 3(4) = 6 + 12 = 18.

Similarly, substituting k = 3, we get d3 = 2d2 + 3[tex](3^2)[/tex] = 2(18) + 3(9) = 36 + 27 = 63.

Based on these calculations, we observe that each term in the sequence is related to the previous term by multiplying it by 2 and adding 3[tex]k^2[/tex]. Moreover, we notice a quadratic pattern in the sequence.

To find the explicit formula, we can express dx in terms of k:

dx = 2dx-1 + 3[tex]k^2[/tex]

  = 2(2dx-2 + 3[tex](k-1)^2[/tex]) + 3[tex]k^2[/tex]

  = 4dx-2 + 6[tex](k-1)^2[/tex][tex](k-1)^2[/tex] + 3[tex]k^2[/tex].

We can continue this iteration process, expanding dx-2 in terms of dx-3, and so on. By continuing this process and simplifying the equation, we find that the explicit formula for the sequence is dx = 3([tex]2^{k-1}[/tex]) + 3[tex]k^2[/tex] - 6k + 3.

In conclusion, by using iteration, we have determined that the explicit formula for the given sequence dx = 2dx-1 + 3[tex]k^2[/tex], with d1 = 3, is dx = 3([tex]2^{k-1}[/tex]) + 3[tex]k^2[/tex] - 6k + 3.

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Answer:

42+123+x=180

x=180-165

x=15 degrees

Step-by-step explanation:

There is insufficient evidence of a significant difference in the proportion of males and females that have at least one tattoo.

Therefore, the correct answer is A.

To construct a confidence interval for the difference in proportions, we can use the following formula:

CI = (p1 - p2) ± Z ×√[(p1×(1 - p1) / n1) + (p2 × (1 - p2) / n2)]

Where:

p1 and p2 are the sample proportions for males and females, respectively.

n1 and n2 are the sample sizes for males and females, respectively.

Z is the critical value corresponding to the desired confidence level.

From the given information, we have:

p1 = 190/1233

n1 = 1233

p2 = 128/1033

n2 = 1033

Confidence level = 99% (which corresponds to a critical value of Z)

Calculating the confidence interval:

CI = (190/1233 - 128/1033) ± Z× √[(190/1233× (1 - 190/1233) / 1233) + (128/1033 ×(1 - 128/1033) / 1033)]

Now, let's find the critical value Z for a 99% confidence level. Since the sample sizes are large, we can use the standard normal distribution. The critical value for a 99% confidence level is approximately 2.576.

CI = (0.154 - 0.124) ± 2.576× √[(0.154× (1 - 0.154) / 1233) + (0.124 × (1 - 0.124) / 1033)]

CI = 0.030 ± 2.576×√[0.000118 + 0.000124]

CI = 0.030 ± 2.576×√(0.000242)

CI = 0.030 ± 2.576×0.015556

CI = 0.030 ± 0.040085

CI ≈ (-0.010, 0.070)

The lower bound of the 99% confidence interval is approximately -0.010, and the upper bound is approximately 0.070.

Interpreting the interval, we can say:

A. There is 99% confidence that the difference of the proportions is in the interval. Conclude that there is insufficient evidence of a significant difference in the proportion of males and females that have at least one tattoo.

Therefore, the correct answer is A.

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Answer:

1733.33

Step-by-step explanation:

The volume of a pyramid is (length*width*height) divided by 3

Answer:

1733.33

Step-by-step explanation:

v = (lwh)/3

v = (20 x 20 x 13)/3 = 5200/3 = 1733.33

Answer:

The answer is B, have a wonderful day!

Step-by-step explanation:

Answer:

10 liters of water

Step-by-step explanation:

Given

[tex]A = 10L\ milk[/tex]

Required

How much the second holds

Since they are both identical, then both containers hold the same volume (even if the quantity they hold are different)

Hence:

[tex]B = 10L\ water[/tex]

Answer: 9 x 6 x 6

Step-by-step explanation: 9 x 6=54  54 x 6 = 324 ft

Answer:

4324eqW

Step-by-step explanation:

3 + 5 =7

Answer:

They a similar because they both had zero as their final answer. Andre decided to do 3 x 200 while Jada  decided to do 3 x 50. Andre work is more complicated and uses big number while Jada's work uses small numbers and are more easier to do.

Step-by-step explanation:

Answer:

its 77 1/3

just do the math with a calculator

Answer: 48 1/3

Step-by-step explanation:

Answer:

106

Step-by-step explanation:

reflection

the test statistic (t = -12.857) is smaller than the critical value (-1.860), we have enough evidence to reject the null hypothesis.

To test the hypothesis regarding the population mean, we can perform a one-sample t-test.

Given:

- Null hypothesis (H₀): μ = 13

- Alternative hypothesis (Hₐ): μ < 13

- Sample mean ([tex]\bar{X}[/tex]) = 10

- Sample standard deviation (s) = 0.7

- Sample size (n) = 9

- Significance level (α) = 0.05

To conduct the t-test, we can calculate the test statistic and compare it with the critical value from the t-distribution.

The test statistic (t-score) is calculated as:

t = ([tex]\bar{X}[/tex] - μ) / (s / √n)

Plugging in the values:

t = (10 - 13) / (0.7 / √9)

t = -3 / (0.7 / 3)

t = -3 / 0.233

t ≈ -12.857

To determine the critical value, we need to find the appropriate degrees of freedom (df) for a one-sample t-test. In this case, df = n - 1 = 9 - 1 = 8.

Using a significance level of α = 0.05 and looking up the critical value for df = 8 in the t-distribution table, we find the critical value to be approximately -1.860.

Since the test statistic (t = -12.857) is smaller than the critical value (-1.860), we have enough evidence to reject the null hypothesis.

Decision: Based on the test results, at α = 0.05, we reject the null hypothesis (H₀: μ = 13). There is sufficient evidence to support the alternative hypothesis (Hₐ: μ < 13), suggesting that the population mean is less than 13.

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Given question is incomplete, the complete question is below

Assuming the sample was taken from a normal population, test at α = 0.05 and state the decision. Họ: μ = 13 HA: μ < 13 [tex]\bar{X}[/tex]= 10 s= 0.7 n = 9

The given values are: Ksp of CaSO4 = 4.93 × 10⁻⁵, Molarity of Na2SO4 = 0.250(m). Molar mass of CaSO4 = 136.14 g/mol. We can write the equation for the dissolution of CaSO4 in water as:CaSO4(s) ⇌ Ca²⁺(aq) + SO₄²⁻(aq). Let's consider that "x" grams of CaSO4 dissolves in "1 L" of 0.250 M Na2SO4. Since the CaSO4 dissolves according to the following equation:CaSO4(s) ⇌ Ca²⁺(aq) + SO₄²⁻(aq). The concentration of Ca²⁺ ions in the solution will be "x" moles / 1 L. The concentration of SO₄²⁻ ions in the solution will be "x" moles / 1 L. Since the concentration of Na2SO4 in the solution is 0.250 M or 0.250 moles / L, the concentration of SO₄²⁻ ions contributed by Na2SO4 will be (2 × 0.250) M or 0.500 M. In order to determine the value of "x" or the amount of CaSO4 that dissolves, we need to consider the equilibrium of the solution. The Ksp expression for the dissolution of CaSO4 can be written as: Ksp = [Ca²⁺][SO₄²⁻], Ksp = (x)(x) = x². As the dissociation is very small compared to the concentration of Na2SO4, we can consider "0.250" moles of Na2SO4 in "1 L" of the solution completely dissociated. Thus, the final concentrations of Ca²⁺ and SO₄²⁻ ions in the solution will be:[Ca²⁺] = x moles / L[SO₄²⁻] = (x + 0.500) moles /L. Therefore, we can write the expression for the ion product: IP = [Ca²⁺][SO₄²⁻]IP = (x)(x + 0.500)As the value of Ksp is equal to the IP, we can write the expression for Ksp as: Ksp = x² + 0.500xWe can substitute the value of Ksp as 4.93 × 10⁻⁵M:4.93 × 10⁻⁵ = x² + 0.500x. Solving for "x", we get the following quadratic equation: x² + 0.500x - 4.93 × 10⁻⁵ = 0. Solving for "x" using the quadratic formula: x = 0.00796 g/L. Therefore, the solubility of CaSO4(s) in 0.250 M Na2SO4 solution at 25°C is 0.00796 g/L.

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Answer:

[tex]y=-|x|+2[/tex]

Step-by-step explanation:

The y-intercept is 2 and the line of symmetry is the y-axis.

1. When a fair die is tossed the expected value E[X1] = 3.5 and the variance var(X1) = 35/12.

When a fair die is tossed, each of the six possible outcomes has an equal probability of 1/6. Let X1 denote the score obtained in the first toss.

To calculate the expected value E[X1], we find the sum of all possible values of X1 multiplied by their respective probabilities:

E[X1] = (1 * 1/6) + (2 * 1/6) + (3 * 1/6) + (4 * 1/6) + (5 * 1/6) + (6 * 1/6) = 3.5

To calculate the variance var(X1), we use the formula:

var(X1) = E[X1^2] - (E[X1])^2

First, we find E[X1^2] by taking the sum of the squares of all possible values of X1 multiplied by their respective probabilities:

E[X1^2] = (1^2 * 1/6) + (2^2 * 1/6) + (3^2 * 1/6) + (4^2 * 1/6) + (5^2 * 1/6) + (6^2 * 1/6) = 91/6

Substituting the values into the formula, we calculate var(X1):

var(X1) = (91/6) - (3.5)^2 = 35/12

Therefore, E[X1] = 3.5 and var(X1) = 35/12.

2. The probability distribution of Y = |X1 - X2| is tabulated as follows:

Y |X1 - X2| P(Y)

0 0 1/6

1 1 2/6

2 2 2/6

3 3 1/6

To calculate E[Y], we find the sum of all possible values of Y multiplied by their respective probabilities:

E[Y] = (0 * 1/6) + (1 * 2/6) + (2 * 2/6) + (3 * 1/6) = 1

Therefore, E[Y] = 1.

3. The statements E(Z^2) = E(Y^2) and Var(Z) = Var(Y) are false.

E(Z^2) and E(Y^2) represent the expected values of the squares of the random variables Z and Y, respectively. Since Z = X1 - X2 and Y = |X1 - X2|, the squares of Z and Y have different probability distributions, leading to different expected values.

Similarly, Var(Z) and Var(Y) represent the variances of Z and Y, respectively. Since Z and Y have different probability distributions, their variances will generally not be equal.

Therefore, E(Z^2) ≠ E(Y^2) and Var(Z) ≠ Var(Y).

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Answer:

b = 6.1 ft

Step-by-step explanation:

The area (A) of a triangle is calculated as

A = [tex]\frac{1}{2}[/tex] bh ( b is the base and h the perpendicular height )

Here A = 10.98 and h = 3.6 , then

[tex]\frac{1}{2}[/tex] × b × 3.6 = 10.98

1.8b = 10.98 ( divide both sides by 1.8 )

b = 6.1

Answer:

12

Step-by-step explanation:

1/5 mint = 6

30 - 6 = 24

Half of 24 is 12

12 is chocolate

so 12 must be vanilla

Answer:

10, 12 and 11

Step-by-step explanation:

On each median , the distance from the vertex to the centroid is twice as long as the distance from the centroid to the midpoint.

TZ = 2 × ZX = 2 × 5 = 10

UY = UZ + ZY = 8 + 4 = 12

ZW = [tex]\frac{1}{3}[/tex] × VW = [tex]\frac{1}{3}[/tex] × 33 = 11

Answer: 11x + 20y ≥ 220

x + y ≤ 15

Hope this helps

9514 1404 393

Answer:

Step-by-step explanation:

The two inequalities represent the two relations described in the problem statement.

  x + y ≤ 15 . . . . . . . Mia works a maximum of 15 hours

  11x + 20y ≥ 220 . . . . Mia makes at least $220

These are graphed in the attachment. The solution area is the doubly-shaded area with vertices at (9, 6), (0, 11) and (0, 15). One possible solution is shown at (3, 11), which represents ...

  3 hours babysitting

  11 hours lifeguarding . . . . . . . . total 14 hours for $253

The correct answer should be 32.

To simplify the expression (4 + 3i)(2 - 8i), we can use the distributive property of multiplication.

First, we multiply the real parts of the two complex numbers:

(4)(2) = 8.

Next, we multiply the imaginary parts of the two complex numbers:

(3i)(-8i) = -24i^2.

Remember that i^2 is defined as -1, so we can substitute -1 for i^2:

-24i^2 = -24(-1) = 24.

Now, we combine the real and imaginary parts:

8 + 24 = 32.

Therefore, the simplified expression is 32.

Since none of the given answer choices match the simplified expression, it appears that there may be an error in the options provided. The correct answer should be 32.

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a.  the value of P(2.4 < x < 3) is 8.1.

b. the value of E(X) is 10.

Given function is f(x) = 5(6)x for x≥1 and elsewhere for a continuous random variable z.  

a. Compute P(2.4 < x < 3)

For continuous random variable, P(a < x < b) = ∫f(x)dx, where f(x) is the probability density function (PDF).

Here, f(x) = 5(6)x for x≥1 and elsewhere

So, P(2.4 < x < 3) = ∫f(x)dx = ∫2.4^35(6)xdx= 5 ∫2.4^36xdx= 5 [(3^2 - 2.4^2)/2] = 5 [(9 - 5.76)/2] = 5 [1.62] = 8.1

Hence, the value of P(2.4 < x < 3) is 8.1.

b. Compute E(X)Expected value of X is given by E(X) = ∫xf(x)dxFor continuous random variable, E(X) = ∫xf(x)dx, where f(x) is the probability density function (PDF).Here, f(x) = 5(6)x for x≥1 and elsewhereSo, E(X) = ∫xf(x)dx = ∫1∞5(6)x.xdx+ ∫-∞0 0dx= 5 ∫1∞6x^2dx+ 0 = 5 [(6) (x^3)/3]1∞= 5 [(6) (1^3)/3] = 10

Hence, the value of E(X) is 10.

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Given f(x)= 5 (6) x for rexeh 1 o elsewhere for a continuous veidon variable z. We are required to compute p(2.4 < x <3) and E(x).

Compute p(2.4 < x <3)For the given function, f(x) = 5 (6) x for 1 ≤ x ≤ 3 and 0 elsewhere.

So, the total area under the curve will be equal to 5 (6) 2 = 60.

And the required probability is given by the area under the curve from 2.4 to 3.  [Illustration is provided below]

Hence, p(2.4 < x <3) = 3.6

(b)Compute E(x)Expected value of x, E(x) is given by E(x) = ∫xf(x) dx,

which is equal to the area under the curve multiplied by the distance over which the function is spread.

Let's calculate the area under the curve, which is equal to 60, as we have calculated earlier.

Now, we calculate the distance over which the function is spread.

Distance = 3 - 1 = 2 unitsHence, E(x) = 60/2 = 30.

Answer:Therefore, p(2.4 < x <3) = 3.6 and E(x) = 30.

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Answer:

Answer:

x²=20² -14²

x²=400-196

x²=204

x=√204

Answer: Y less than -3x – 3

Step-by-step explanation:

Answer:

1/3 or 33%

Step-by-step explanation:

15 + 15 + 20 +25 is equal to 75

25/75 is 1/3

Answer:

1 by 3

Step-by-step explanation:

15 + 15 + 20 + 25 = 75

so,

again,