Ask question

Ask question

All categories

3 years ago

5

Holly is going to draw two cards from a standard deck without replacement. What is the probability that the first card is a king

and the second card is an ace?

1 answer:

Sauron [17]3 years ago

4 0

1/13 chance for king and ace 8/52

You might be interested in

Create the equation of a line that is perpendicular to 2y=14+(2/3) x and passes through the point (-2,8).

anzhelika [568]

Answer:

y = -3x +2

Step-by-step explanation:

If you divide the equation for the given line by 2, it will be in slope-intercept form:

y = (1/3)x +7

This tells you its slope is 1/3. The slope of the perpendicular line is the negative reciprocal of this: -1/(1/3) = -3. The point-slope form of the equation for the perpendicular line can be written as ...

y = m(x -h) +k . . . . . line with slope m through point (h, k)

Your line is ...

y = -3(x -(-2)) +8

y = -3x +2

6 0

2 years ago

Given: ∠AOB is a central angle and ∠ACB is a circumscribed angle. Prove: △ACO ≅ △BCO Circle O is shown. Line segments A O and B

charle [14.2K]

Answer:

all radii of the same circle are congruent

tangents to a circle that intersect are congruent

side CO is congruent to side CO

SSS congruency theorem

Step-by-step explanation:

6 0

3 years ago

Read 2 more answers

Some scientists believe alcoholism is linked to social isolation. One measure of social isolation is marital status. A study of

frez [133]

Answer:

1) H0: There is independence between the marital status and the diagnostic of alcoholic

H1: There is association between the marital status and the diagnostic of alcoholic

2) The statistic to check the hypothesis is given by:

$\sum_{i=1}^n \frac{(O_i -E_i)^2}{E_i}$

3) $\chi^2 = \frac{(21-33.143)^2}{33.143}+\frac{(37-41.429)^2}{41.429}+\frac{(58-41.429)^2}{41.429}+\frac{(59-46.857)^2}{46.857}+\frac{(63-58.571)^2}{58.571}+\frac{(42-58.571)^2}{58.571} =19.72$

4) $df=(rows-1)(cols-1)=(3-1)(2-1)=2$

And we can calculate the p value given by:

$p_v = P(\chi^2_{2} >19.72)=5.22x10^{-5}$

And we can find the p value using the following excel code:

"=1-CHISQ.DIST(19.72,2,TRUE)"

Since the p value is lower than the significance level so then we can reject the null hypothesis at 5% of significance, and we can conclude that we have association between the two variables analyzed.

Step-by-step explanation:

A chi-square goodness of fit test "determines if a sample data matches a population".

A chi-square test for independence "compares two variables in a contingency table to see if they are related. In a more general sense, it tests to see whether distributions of categorical variables differ from each another".

Assume the following dataset:

Diag. Alcoholic Undiagnosed Alcoholic Not alcoholic Total

Married 21 37 58 116

Not Married 59 63 42 164

Total 80 100 100 280

Part 1

We need to conduct a chi square test in order to check the following hypothesis:

H0: There is independence between the marital status and the diagnostic of alcoholic

H1: There is association between the marital status and the diagnostic of alcoholic

The level os significance assumed for this case is $\alpha=0.05$

Part 2

The statistic to check the hypothesis is given by:

$\sum_{i=1}^n \frac{(O_i -E_i)^2}{E_i}$

Part 3

The table given represent the observed values, we just need to calculate the expected values with the following formula $E_i = \frac{total col * total row}{grand total}$

And the calculations are given by:

$E_{1} =\frac{80*116}{280}=33.143$

$E_{2} =\frac{100*116}{280}=41.429$

$E_{3} =\frac{100*116}{280}=41.429$

$E_{4} =\frac{80*164}{280}=46.857$

$E_{5} =\frac{100*164}{280}=58.571$

$E_{6} =\frac{100*164}{280}=58.571$

And the expected values are given by:

Diag. Alcoholic Undiagnosed Alcoholic Not alcoholic Total

Married 33.143 41.429 41.429 116

Not Married 46.857 58.571 58.571 164

Total 80 100 100 280

And now we can calculate the statistic:

$\chi^2 = \frac{(21-33.143)^2}{33.143}+\frac{(37-41.429)^2}{41.429}+\frac{(58-41.429)^2}{41.429}+\frac{(59-46.857)^2}{46.857}+\frac{(63-58.571)^2}{58.571}+\frac{(42-58.571)^2}{58.571} =19.72$

Part 4

Now we can calculate the degrees of freedom for the statistic given by:

$df=(rows-1)(cols-1)=(3-1)(2-1)=2$

And we can calculate the p value given by:

$p_v = P(\chi^2_{2} >19.72)=5.22x10^{-5}$

And we can find the p value using the following excel code:

"=1-CHISQ.DIST(19.72,2,TRUE)"

Since the p value is lower than the significance level so then we can reject the null hypothesis at 5% of significance, and we can conclude that we have association between the two variables analyzed.

7 0

3 years ago

For what values do maximum r-values occur on the graph the polar equation

blagie [28]

Answer:

We have the function:

r = -3 + 4*cos(θ)

And we want to find the value of θ where we have the maximum value of r.

For this, we can see that the cosine function has a positive coeficient, so when the cosine function has a maximum, also does the value of r.

We know that the meaximum value of the cosine is 1, and it happens when:

θ = 2n*pi, for any integer value of n.

Then the answer is θ = 2n*pi, in this point we have:

r = -3 + 4*cos (2n*pi) = -3 + 4 = 1

The maximum value of r is 7

(while you may have a biger, in magnitude, value for r if you select the negative solutions for the cosine, you need to remember that the radius must be always a positive number)

5 0

3 years ago

Read 2 more answers

What number added to 66 is 167

denis-greek [22]

Answer:

101

Step-by-step explanation:

To figure this out, you would do 167 - 66 = 101

101 + 66 = 167

5 0

2 years ago