Statistics and Probability Answers

A steel rod is subjected to stress. The tensile strength of the rod at different values of the stress are

recorded. Find a relation between the tensile strength and the stress. The data is given below:

Stress (kg): 10 9 7 8 11

Tensile strength: 6 3 2 4 5

Also predict the tensile strength at a stress of 5 kg

A cricket ball manufacturing company wants to check the variation in the weight of the balls. For

this, 25 samples each of size 4, are selected and the weight of each ball is measured (in grams). The

sum of the sample average and the sum of Sample ranges were found to be ∑25 1 xi = 4010 Grams

and ∑25 ri = 72 grams, respectively. Computer the control limits for the X and R-charts. It is

given that A2 = 0.729, D3 = 0 and D4 = 2.282

If a baseball player's batting average is 0.340 ( i.e., the probability of getting a hit each time at bat is 0.340), find the probability that the player will have a bad season and get at most 60 hits in 200 times at bat?

Find the area under the standard normal curve to the right of z=−1.25

1. A presidential candidate asks a polling organization to conduct a nationwide survey to determine the percentage of potential voters who would vote for him over his rival presidential candidate. Out of 2500 respondents in the sample, 925 said they would vote for him. If 40% of the potential voters vote for his rival, is this significantly different from the percentage of potential voters of the candidate who requested the survey? Use 5% level of significance.

What is parameter and statics in Sampling?

The joint pdf of random variables ‘X’ and ‘Y’ is

Find

a. The marginal pdfs, f_X(x) and f_Y(y).

b. The conditional pdfs, f_X/Y(x/y) and f_Y/X(y/x)

c. The E(X/Y=1)

d. Are ‘X’ and ‘Y’ statistically independent?

For a certain binary communication channel, the probability a transmitted ‘0’ bit is received as a ‘0’ bit is 0.95 and for ‘1’ bit, it is 0.90. The probability that ‘0’ bit is transmitted is 0.4, Find

a. Probability that ‘1’ bit is received.

Arterial blood gas analyses performed on a sample of 15 physically active adult males yielded the following resting values: 75, 80, 80, 74, 84, 78, 89, 72, 83, 76, 75, 87, 78, 79, 88 Compute the 90 and 95 percent confidence interval for the mean of the population