Two equivalent ratios for 14/8

An urn contains 12 balls, of which 4 are white.

wel

Answer:

a) $\frac{1}{3}$

b) $\frac{4}{12}\,,\,\frac{4}{11}\,,\,\frac{4}{10}\,,...$

Step-by-step explanation:

Number of balls in the urn = 12

Number of white balls in the urn = 4

So, number of balls which are not white = 12 - 4 = 8

We know that probability = No. of outcomes/Total number of outcomes

Let $A_i\,,\,B_i\,,\,C_i$ denotes the event of getting white ball by A, B and C

a) each ball is replaced after being drawn.

Probability = Number of white balls/Total number of balls

Solution: $P(A_i)=P(B_i)=P(C_i)=\frac{4}{12}=\frac{1}{3}$

b)the balls that are withdrawn are not replaced.

Solution:

If A wins: $P(A_1)=\frac{4}{12}=\frac{1}{3}$

If A lost and B wins: $P\left ( B_1|A_1^{c} \right )=\frac{4}{11}$

If A and B lost and C wins: $P\left ( C_1|A_1^{c}\,B_1^{c} \right )=\frac{4}{10}$

and so on....

4 0

3 years ago

What is an equation of the line that passes through the point (2,−6) and is parallel to the line x−2y=8?

lorasvet [3.4K]

Answer:

y = x/2 - 7

Step-by-step explanation:

First, we need to find the slope of the given equation: x - 2y = 8

Subtract x from both sides

x - 2y = 8

- x - x

-2y = 8 - x

Divide both sides by -2

-2y/-2 = (8 - x)/-2

y = -4 + x/2

The slope of this equation is 1/2

So the equation of our parallel equation is y = x/2 + b

We have to find b, so plug in the given coordinates

-6 = 2/2 + b

-6 = 1 + b

Subtract 1 from both sides

-6 = 1 + b

- 1 - 1

b = -7

Plug it back into the original equation

y = x/2 - 7

6 0

2 years ago

In a simple random sample of 14001400 young people, 9090% had earned a high school diploma. Complete parts a through d below.

ratelena [41]

Answer:

(a) The standard error is 0.0080.

(b) The margin of error is 1.6%.

(c) The 95% confidence interval for the percentage of all young people who earned a high school diploma is (88.4%, 91.6%).

(d) The percentage of young people who earn high school diplomas has increased.

Step-by-step explanation:

Let p = proportion of young people who had earned a high school diploma.

A sample of n = 1400 young people are selected.

The sample proportion of young people who had earned a high school diploma is:

$\hat p=0.90$

(a)

The standard error for the estimate of the percentage of all young people who earned a high school diploma is given by:

$SE_{\hat p}=\sqrt{\frac{\hat p(1-\hat p)}{n}}$

Compute the standard error value as follows:

$SE_{\hat p}=\sqrt{\frac{\hat p(1-\hat p)}{n}}$

$=\sqrt{\frac{0.90(1-0.90)}{1400}}\\$

$=0.008$

Thus, the standard error for the estimate of the percentage of all young people who earned a high school diploma is 0.0080.

(b)

The margin of error for (1 - α)% confidence interval for population proportion is:

$MOE=z_{\alpha/2}\times SE_{\hat p}$

Compute the critical value of z for 95% confidence level as follows:

$z_{\alpha/2}=z_{0.05/2}=z_{0.025}=1.96$

Compute the margin of error as follows:

$MOE=z_{\alpha/2}\times SE_{\hat p}$

$=1.96\times 0.0080\\=0.01568\\\approx1.6\%$

Thus, the margin of error is 1.6%.

(c)

Compute the 95% confidence interval for population proportion as follows:

$CI=\hat p\pm MOE\\=0.90\pm 0.016\\=(0.884, 0.916)\\\approx (88.4\%,\ 91.6\%)$

Thus, the 95% confidence interval for the percentage of all young people who earned a high school diploma is (88.4%, 91.6%).

(d)

To test whether the percentage of young people who earn high school diplomas has increased, the hypothesis is defined as:

H₀: The percentage of young people who earn high school diplomas has not increased, i.e. p = 0.80.

Hₐ: The percentage of young people who earn high school diplomas has not increased, i.e. p > 0.80.

Decision rule:

If the 95% confidence interval for proportions consists the null value, i.e. 0.80, then the null hypothesis will not be rejected and vice-versa.

The 95% confidence interval for the percentage of all young people who earned a high school diploma is (88.4%, 91.6%).

The confidence interval does not consist the null value of p, i.e. 0.80.

Thus, the null hypothesis is rejected.

Hence, it can be concluded that the percentage of young people who earn high school diplomas has increased.

8 0

3 years ago

One sandwich is shared equally among eight people. How much will each person get

givi [52]

Answer:

1/8 of a sandwich

3 0

3 years ago

Read 2 more answers

Grace is an hourly employee, and the line that models her total pay in dollars

tresset_1 [31]

Answer: Hello mate!

if x is the amount of hours worked, 45 is the slope and the y intercept is 35.

A linear equation has the form of y = ax + b, where a is the slope and b is the y-intercept, then the equation that we have is:

y = 45*x + 35

this means that she wins $45 per hour, and has a plane amount of $35, indiferent of the amount of hours worked.

Then the correct answer is

C) Grace's wage is $45 an hour, and it appears that she received a signing bonus of $35.

5 0

3 years ago

Read 2 more answers