Statistics and Probability Answers

ACTIVITY: Problem: The scores of individual students on a national achievement test have a normal distribution with a mean of 20.8 and a standard deviation of 1.9. At Feliciano Delos Santos High School, 84 students took the test. If the scores of the students at this school have the same distribution as the national scores, how will you describe the sampling distribution of the scores of these students? Assume that the population is infinite. Use the given steps above

In a graduate teacher college, a survey was conducted to determine the proportion of students who want to major in mathematics. If 368 out of 850 students said yes, with 95% confidence, what interpretation can we make regarding the probability that all students in the teacher graduate college want to major in mathematics?

The population mean length of piece of yarn is 230 inches with standard deviation of 14 inches. A sample of 60 pieces of the yarn was taken. What is the probability that the sample mean differs from the population mean by atleast 1.25 inches?

It is claimed that the average weight of a bag of biscuits is 250 grams with a standard deviation of 20.5 grams. Would you agree to this claim if a random sample of 50 bags of biscuits showed an average weight of 240 grams, using a 0.05 level of significance?

It is claimed that the average weight of a bag of biscuits is 250 grams with a standard deviation of 20.5 grams Would you agree to this claim if a random

A family has 3 boys and 5 girls. In how many ways can their parents choose a basketball team of 5 people? Include evidence of your work by typing our your solution.

The results of the final exam in General Mathematics of the 12 sections of Grade 1

are normally distributed with u = 82and o = 13. What is the percentile rank of a score o

85

A percentile rank of 85 means you have to find the percentage of scores below 85. T

find the required area in the Z-table, transform 85 to a z-score

1. Convert the raw score of 85 to a z-score

2. Draw the normal curve showing the z-score.

3.Draw a line through the z-score and shade the required region.

(Note : In the problem, the required region is below the computed z-score since you are looking for the percentile rank)

4. Use the table and find the area that corresponds to the computed z-score.

5. Examine the shaded region and make an appropriate operation apply

6. Compute the percentile rank of the score. (Hint: Multiply the probability in decimal by 100 to get the desired percentage)

AUS Rural Bank is studying the relationship between the mean account balance for individual accounts and the number of transactions per month. A sample of eight accounts revealed:

customer 1 2 3 4 5 6 7 8

Mean balance 50 32 53 24 15 10 16 27

No of transactions 5 2 7 9 10 2 4 11

Find the coefficient of correlation. Determine at the 0.01 significance level whether the correlation in the population is greater than zero.

Step 1: state the hypotheses,

Ho: __________________________________________________________

H1: __________________________________________________________

Step 2: The level of significance and critical region: α=__________

And t critical______________

Step 3: Complete the table and compute for the value of r and t

customer X Y X2 Y2 XY

1

2

3

4

5

6

7

8

∑▒〖X=〗

∑▒Y=

∑▒〖X^2=〗

∑▒〖Y^2=〗

∑▒〖XY=〗

r=

tcomputed=

Step 4: Decision rule:

Step 5: Conclusion

The following data represents the students' scores :

(81,35,86,91,69,72,47,66,80,55,90,53,43,56,80,77,59)

Wanted to find :

1_SMA 2 Mediator 3_ Vein

4_Term 5_standard deviation 6_Variance

The following data represents the students' scores :

(81,35,86,91,69,72,47,66,80,55,90,53,43,56,80,77,59)

Wanted to find:

standard deviation