Math Answers

A process has been developed that can transform ordinary iron into a kind of super iron called metallic glass. Metallic glass is three to four times stronger than the toughest steel alloys. To estimate the mean temperature at which a particular type of metallic glass becomes brittle, 20 pieces of this material were randomly sampled from a recent production run. Each piece was subjected to higher and higher temperatures until it became brittle. The temperature at which brittleness first appeared was recorded for each piece in the sample. The result suggests that the average temperature which brittleness first appeared is about 545 degrees Fahrenheit with a standard deviation of 27 degrees Fahrenheit. Calculate the length of the 95% confidence interval for the mean temperature at which a particular type of metallic glass becomes brittle.

Find dy/dx for the equation y= 3x-5/×^2-4x

Solve the sample mean and the probability of each sample mean by constructing all random samples consisting of two observations from the given data. 

Watermelon    

A

B

C

D

E

F

Weight (in pounds)

19

14

15

9

10

17

The number of inquiries received per day by the Office of Admissions in a certain university is shown below. Find the variance

and standard deviation.

Number of inquiries: 20, 21,22,23,24,25, 26

Probability: 0.07, 0.17, 0.26, 0.31, 0.2, 0.13,0.12

The number of inquiries received per day by the Office of

Admissions in a certain university is shown below. Find the variance

and standard deviation.

Number of inquiries: 20, 21,22,23,24,25, 26

Probability: 0.07, 0.17, 0.26, 0.31, 0.2, 0.13,0.12

Let Q (x,) be the statement “the word x contains the letter a.” What are the truth values of the following?

a) P(orange)

b) P(lemon)

c) P(true)  

d) P(false) 

1.    Determine whether this proposition is a tautology.

[(p → q) ∧ (q → r)] → (p→ r) 

Determine whether this proposition is a tautology.

[(p → q) Ù (q → r)] → (p→ r) 

A population consists of the five measurements 2, 6, 8, 3 & 1. How many different

samples of size n = 2 can be drawn from the population? What is the mean & variance

of the sampling distribution of the sample means? Follow steps 1 to 6.

a population consisits of four numbers (3,8,10,15) consider all the possible sample of size 2 that can be drawn without replacement from the population find the following

a.find the population mean

b. find the population varince

c.find the population standard deviation

d.find the possible sample of size 2 which can be drawn without replacement from this population

e.find the mean of the sampling distribution of means

f.find the varience of the sampling distribution of means

g.find the standard deviation of the sampling distribution of means .