Bailey got a 75% on a quiz. They got 15 questions

A padlock has a four-digit code that includes digits from 0 to 9, inclusive. What is the probability that the code does not cons

Eduardwww [97]

Since there is no repetition allowed, there are 10 possibilities for the 1st digit, 9 for the 2nd, 8 for the 3rd, and 7 for the 4th. This gives a total of (10)(9)(8)(7) = 5040 four-digit codes.
For all odd digits to be used, there are 5 possibilities for the 1st digit (1,3,5,7,9), 4 for the 2nd, 3 for the 3rd, 2 for the 4th. This gives a total of (5)(4)(3)(2) = 120 codes that only use odd digits.
Therefore there are 5040 - 120 = 4920 codes that do not consist of all odd digits. The probability is 4920/5040 = 41/42.

4 0

2 years ago

Read 2 more answers

Find the distance between the two points on the coordinate plane.

Jobisdone [24]

Answer:

10

Step-by-step explanation:

Assuming that each square is one unit, you plug it into the distance formula.

4 0

2 years ago

A bookshelf is 45 inches wide. How many 1 & 1/2 inch wide books will fit on the bookshelf? *

andriy [413]

Answer:

30 books

Step-by-step explanation:

bookshelf is 45 inches

each book is 1 1/2 inches

45 / 1 1/2 = 30

30 books can fit on the shelf

7 0

2 years ago

John is creating crafts that require 4 2/5 inches of string each. If the string comes in a 50ft spool, how many items can he mak

Serggg [28]

Answer:

Step-by-step explanation:

7 0

3 years ago

A market research team thinks that their new ad campaign is better than their old one. They used to be able to sell to 50% of th

andreev551 [17]

Answer:

a. The test statistic is 2 and we conclude that the new ad campaign is not signficantly better.

Step-by-step explanation:

They used to be able to sell to 50% of those who saw their ads. Test if the new campaign is better.

At the null hypothesis, we test is it is the same, that is, the proportion is the same.

$H_0: p = 0.5$

At the alternate hypothesis, we test if it is significantly better, that is, the proportion is above 50%.

$H_1: p > 0.5$

The test statistic is:

$z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}$

In which X is the sample mean, $\mu$ is the value tested at the null hypothesis, $\sigma$ is the standard deviation and n is the size of the sample.

0.5 is tested at the null hypothesis:

This means that $\mu = 0.5, \sigma = \sqrt{0.5*0.5} = 0.5$

They take a random sample of 100 potential buyers and find that they convinced 60 of these people to buy their product.

This means that $n = 100, X = \frac{60}{100} = 0.6$

Test statistic:

$z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}$

$z = \frac{0.6 - 0.5}{\frac{0.5}{\sqrt{100}}}$

$z = 2$

The test statistic is 2.

P-value of the test and decision:

The p-value of the test is the probability of finding a sample proportion above 0.6, which is 1 subtracted the by p-value of z = 2.

Looking at the z-table, z = 2 has a p-value of 0.9772.

1 - 0.9772 = 0.0228.

The p-value of the test is 0.0228 > 0.01, which means that we cannot conclude that the new ad campaign is signficantly better, so the correct answer is given by option A.

5 0

3 years ago