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The weights of adobe bricks used for construction are normally distributed with a mean of 3 pounds and a standard deviation of 0.25 pound. Assume that the weights of the bricks are independent and that a random sample of 28 bricks is selected. Round your answers to four decimal places (e.g. 98.7654). (a) What is the probability that all the bricks in the sample exceed 2.75 pounds? (b) What is the probability that the heaviest brick in the sample exceeds 3.75 pounds?

Answers

Answer 1

Answer:

Answer: a) 0.8413, b) 0.9987.

Step-by-step explanation:

Since we have given that

Mean = 3 pounds

Standard deviation = 0.25 pounds

n = 28 bricks

So, (a) What is the probability that all the bricks in the sample exceed 2.75 pounds?

$P(X>2.75)\n\n=P(z>(2.75-3)/(0.25)\n\n=P(z>(-0.25)/(0.25))\n\n=P(z>-1)\n\n=0.8413$

b) What is the probability that the heaviest brick in the sample exceeds 3.75 pounds?

$P(X>3.75)\n\n=P(z>(3.75-3)/(0.25))\n\n=P(z>(0.75)/(0.25))\n\n=P(z>3)\n\n=0.9987$

Hence, a) 0.8413, b) 0.9987.

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Please help will definitely say thanks

Answers

Answer:

$\mathrm{Image \: below.}$

Explanation:

Ruby talks about a 3D shape, so sphere.

Shriya talks about the points that are equal in distance from the opposite points, the diameter, she is right.

Abhishek's definition is not shown completely in the photo, so by process of elimination, he is incorrect.

Factor completely 56 s to the second power + 23 SW - 63 W to the second power

Answers

(8s-7w)(7s+9w) is the complete factored form.

Write the prime factorization of 20 using exponents

Answers

Prime factorization expresses an integer in terms of multiples of prime numbers. The prime factorization of 20 using exponents can be written as 2²×5¹.

What is prime factorization?

Factorization is expressing a mathematical quantity in terms of multiples of smaller units of similar quantities.

Prime factorization is when all those factors are prime numbers.

Thus, prime factorization expresses an integer in terms of multiples of prime numbers.

The prime factorization of 20 using exponents can be written as,

20 = 1 × 2 × 2 × 5

= 2² × 5¹

Hence, the prime factorization of 20 using exponents can be written as 2²×5¹.

Learn more about prime factorization here:

brainly.com/question/10454590

#SPJ2

Here you go

2 to the second power times 5

A scientist has two solutions, which she has labeled Solution A and Solution B. Each contains salt. She knows that Solution A is 70% salt and Solution B is 95% salt. She wants to obtain 150 ounces of a mixture that is 75% salt. How many ounces of each solution should she use?

Answers

Answer:

Solution A: 120 ounces

Solution B: 30 ounces

Step-by-step explanation:

Let's call A the amount of Solution A. Solution A is 70% salt

Let's call B the amount of Solution B. Solution A is 95% salt

The resulting mixture should have 75% salt and 150 ounces .

Then we know that the total amount of mixture will be:

$A + B = 150$

Then the total amount of salt in the mixture will be:

$0.7A + 0.95B = 0.75 * 150$

$0.7A + 0.95B = 112.5$

Then we have two equations and two unknowns so we solve the system of equations. Multiply the first equation by -0.95 and add it to the second equation:

$-0.95A -0.95B = 150 * (-0.95)$

$-0.95A -0.95B =-142.5$

$0.7A + 0.95B = 112.5$

--------------------------------------

$-0.25A = -30$

$A = (-30)/(-0.25)$

$A = 120\ ounces$

We substitute the value of A into one of the two equations and solve for B.

$120 + B = 150$

$B = 30\ ounces$

Plzzzzzzzzzzzzz hellllllllllllllllllllllllllpppppppppppppppppp

Answers

Answer:

1.02 units3

Step-by-step explanation:

18/15 =1.02

Answer is 1.02 ......

A popcorn company builds a machine to fill 1 kg bags of popcorn. They test the first hundred bags filled and find that the bags have an average weight of 1,040 grams with a standard deviation of 25 grams. 1.) Fill out the normal distribution curve for this situation. 2.) What percentage of people would receive a bag that had a weight greater than 1115 grams?

Answers

Answer:

Step-by-step explanation:

Given that a popcorn company builds a machine to fill 1 kg bags of popcorn. They test the first hundred bags filled and find that the bags have an average weight of 1,040 grams with a standard deviation of 25 grams.

i.e. Sample mean = 1040 and

Sample std dev s = 25 gm

Sample size n = 100

Hence by central limit theorem we have the sample mean follows a normal distribution with mean =1040 and std dev = s = 25 gm

$\bar X = N(1040,25)$

Normal curve would be with mean 1040 and std deviatin 25

b) P(X>1115)

= 1-0.9987

=0.0013

i.e. 0.13% would receive a bag that had a weight greater than 1115 grams

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You can use both the t statistic and the z statistic to test hypotheses about the mean of population. The test that uses the t statistic is typically referred to as a t test, while the test that uses z statistic is commonly called a z test. Which of the following statements are true of the t statistic? Check all that apply. The t statistic uses the same formula as the z statistic except that the t statistic uses the estimated standard error in the denominator. The t statistic provides an excellent estimate of z, particularly with small sample sizes. The formula for the t statistic is t = (M – μ) / σM. The t statistic does not require any knowledge of the population standard deviation.