{x | x is the reciprocal of a natural number}

Write two ratios that are equivalent to 1:1

Zolol [24]

4:4 and 5:5 are <span> two ratios that are equivalent to 1:1</span>

3 0

2 years ago

The sale bin in a clothing store contains an assortment of t-shirts in different sizes. There are 7 small, 8 medium, and 4 large

umka21 [38]

Answer:

P(at least 1 large) = 0.648

P(at least 1 large) = 64.8%

Step-by-step explanation:

We have 7 small shirts, 8 medium shirts and 4 large shirts

Total number of shirts = 7 + 8 + 4 = 19 shirts

The probability that at least one of the first four shirts he checks is a large is given by

P(at least 1 large) = 1 - P(no large)

So first we need to find the probability that the none of the first four shirts he checks are large.

For the first check, there are 15 small and medium shirts and total 19 shirts so,

15/19

For the second check, there are 14 small and medium shirts and total 18 shirts left so,

14/18

For the third check, there are 13 small and medium shirts and total 17 shirts left so,

13/17

For the forth check, there are 12 small and medium shirts and total 16 shirts left so,

12/16

the probability of not finding the large shirt is,

P(no large) = 15/19*14/18*13/17*12/16

P(no large) = 0.352

Therefore, the probability of finding at least one large shirt is,

P(at least 1 large) = 1 - P(no large)

P(at least 1 large) = 1 - 0.352

P(at least 1 large) = 0.648

P(at least 1 large) = 64.8%

4 0

2 years ago

A Gallup Poll used telephone interviews to survey a sample of 1030 U.S. residents over the age of 18 regarding their use of cred

Vlada [557]

Answer:

The 95% margin of error for this estimate is 0.0274 = 2.74 percentage points.

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of $\pi$ , and a confidence level of $1-\alpha$ , we have the following confidence interval of proportions.

$\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}$

In which

z is the zscore that has a pvalue of $1 - \frac{\alpha}{2}$ .

The margin of error is:

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

95% confidence level

So $\alpha = 0.05$ , z is the value of Z that has a pvalue of $1 - \frac{0.05}{2} = 0.975$ , so $Z = 1.96$ .

72% of Americans said that they had at least one credit card

This means that $p = 0.72$

Give the 95% margin of error for this estimate.

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

$M = 1.96\sqrt{\frac{0.72*0.28)}{1030}} = 0.0274$

The 95% margin of error for this estimate is 0.0274 = 2.74 percentage points.

7 0

3 years ago

Sixty people purchase raffle tickets. Three winning tickets are selected at random. If each prize is $3000, in how many differen

Alexus [3.1K]

Answer: $^{60}C_{3}$ ways.

Step-by-step explanation:

$^{n}C_{k}$ is the number of ways in which $k$ distinct objects are selected from a pile of $n$ distinct objects.

In our question,there are a total of $60$ people.

So, $n=60$ .

Given that three are selected at random.

So, $k=3$ .

So,the answer is $^{60}C_{3}$ ways.

5 0

2 years ago

If two points on line l above have coordinates (0, A) and (2, −3), and the slope of the line is A, then what is the value of A?

Vlada [557]

Answer:

A = -1

So, option (B) is the correct answer.

Step-by-step explanation:

The two points on line have coordinates: p (x₁, y₁) = (0, A) and q(x₂, y₂) = (2 , -3)

Slope of line = A

Slope of line = $\frac{y_{2} - y_{1}}{x_{2} -x_{1}}$

Now since the slope of line is A and its has two coordinates (0, A) and (2 , -3), ∴

$A = \frac{y_{2} - y_{1}}{x_{2} -x_{1}}$

$A = \frac{-3 - A}{2 - 0}$

$2A = -3 - A$

$2A + A = -3$

$3A = -3$

$A = -1$

So, option (B) is the correct answer.

6 0

2 years ago