# Descriptive statistics Problems Worth Solving, Questions and Answers

- Researcher is using data for a sample of 10 observations to estimate the relation between consumption expenditure and income. Preliminary analysis of the sample data produces the following data. ∑xy = 700 , 1000 2 ∑x = , ∑X = 1…
- The average monthly salary of 525 public school teachers in a municipality is P18925. 150 public school teachers were interviewed and found out they are receiving an average monthly salary of P17000. Identify the following: 1. Popula…
- A box contains 5 balls. One is numbered 1, three are numbered 2, and one is numbered 3. The balls are mixed and one is selected at random. After a ball is selected, its number is recorded. Then it is replaced. If the experiment is rep…
- The manufacturer of the Horizon truck tire claims that the mean mileage the tire can be driven before the tread wears out is 60,000 miles. Assume the mileage wear follows the normal distribution and the standard deviation of the distr…
- A labor union claims “40% of those persons who retired from an industrial job before the age of 60 would return to work if a suitable job were available” 74 persons out of the 200 sampled said they would return to work. Can we conclud…
- A labor union claims “40% of those persons who retired from an industrial job before the age of 60 would return to work if a suitable job were available” 74 persons out of the 200 sampled said they would return to work. Can we conclud…
- There are two octahedral dice with faces marked 1 through 8. They are constructed such that the side 8 is 1.5 times as probable as the 2 through 7 and the sum of the probabilities of the 1 and the 8 equals that of the pairs on opposin…
- There are two octahedral dice with faces marked 1 through 8. They are constructed such that the side 8 is 1.5 times as probable as the 2 through 7 and the sum of the probabilities of the 1 and the 8 equals that of the pairs on opposin…
- Suppose two dice was rolled. Let Y be the random variable representing the number of even number that occur. Find the values of the random variable Y.
- 1. For each of the following scenarios, give an example of a discrete and a continuous random variable. The first one is done as an example. Scenarios •Asking your classmates about their breakfast. •Making an order at a fast foo…
- Among 250 employees, of the local office of an international insurance company, 182 are whites, 51 are blacks and the rest are Orientals. If 5% margin of error is used, 5. How many employees will be chosen for a case study as sample…
- A population is normally distributed with a population mean of 76 and a population standard deviation of 13. i. State the distribution of the sample mean for simple random samples of size n = 100. ii. Given a simple random sample …
- Given a standard normal distribution with mean =78 and standard deviation = 28, find P(85 < X < 102)
- Given a standard normal distribution with mean =118 and standard deviation = 29, find P(76 < X < 144)
- Given a standard normal distribution with mean =136 and standard deviation = 39, find P(X>84)
- Given a standard normal distribution with mean =62 and standard deviation = 44, find P(X>92)
- Given a standard normal distribution with mean =58 and standard deviation = 40, find P(X<96)
- Given a standard normal distribution with mean =60 and standard deviation = 35, find P(X<75)
- An electrical firm manufactures light bulbs that have a length of life that is normally distributed with mean equal to 814 hours and a standard deviation of 42 hours. Find the probability that a bulb burns between 747 and 846 hours.
- An electrical firm manufactures light bulbs that have a length of life that is normally distributed with mean equal to 799 hours and a standard deviation of 49 hours. Find the probability that a bulb burns between 769 and 878 hours.
- The weights of 1,000 children, in average, is 50kg with standard deviation of 14kg. Suppose the weights are normally distributed, how many children weigh between 53kg and 68kg?
- The weights of 1,000 children, in average, is 46kg with standard deviation of 20kg. Suppose the weights are normally distributed, how many children weigh less than 63kg?
- The weights of 1,000 children, in average, is 55kg with standard deviation of 17kg. Suppose the weights are normally distributed, how many children weigh greater than 38kg?
- A random sample of size 144 is drawn from a population whose distribution, mean, and standard deviation are all unknown. The summary statistics are x−−=58.2 and s = 2.6.
- A box contains 5 balls. One is numbered 1, three are numbered 2, and one is numbered 3. The balls are mixed and one is selected at random. After a ball is selected, its number is recorded. Then it is replaced. If the experiment is rep…
- •Box A and B contains 1, 2, 3, 4. Construct the probability distribution and draw a histogram of the sum when one number from each box is taken with placement
- How many ways 6 delegates to the convention from a group of 24 qualified students
- In how many ways can a teacher select 6 delegates to a national convention from a group of 24 students
- The scores for a mathematics course seem to be normally distributed with mean 70 & standard deviation of 8. If the instructor wishes to give an A grade to 10% of the students, what should be the dividing line between an A grade and a …
- suppose the weight of 800 students are normally distributed with mean 75kg and standard deviation 5kg. find the numer of students that weigh more than 80kg
- Suppose that the bank customers arrive randomly and independently on an average of 3.2 customers every 4 minutes. What is the probability that: a. Exactly two customers arrive in every 4 minutes? b. Exactly two customers will arriv…
- Oranges chosen at random have a mean mass of 210 grams and standard deviation of 35 grams. Assuming a normal distribution, what is the probability of choosing an orange with a mass between 170 grams and 250 grams
- To compare the results of boys and girls in a class, a special test was given to 50 boys who averaged 67.4 with Sd. of 5.0, and 50 girls averaged 62.8 with Sd. of 4.6. (Group Assignment) (2 pts.) a) Test, at …
- To compare the results of boys and girls in a class, a special test was given to 50 boys who averaged 67.4 with Sd. of 5.0, and 50 girls averaged 62.8 with Sd. of 4.6. (Group Assignment) (2 pts.) a) Test, at 0.05 …
- Let X be a binomial(5, 0.2) random variable. Let Y be a discrete random variable that is independent of X, such that Y = 1 with probability 0.2 and Y = 0 with probability 0.8. What is the probability that the sum of X and Y is less th…
- 1 4 4 2 3 4 5 1 4 1 Work out the mode
- Regression of yi = ꞵ0 + ꞵ1 xi1 + ꞵ2 xi2 + ꞵ3 xi3 + ꞵ4 xi4 + ui yields the following results in tabular form. The tabulated t- statistics is 2.6 , 1.96 and 1.64 for one , five and ten percent significance levels respectively. State the…
- a) Consider the following functional relation, f, defined as: f : R \rightarrow R, f(x) = x2 Determine whether or not f is a bijection. If it is, prove it. If it is not, show why it is not. b) Consider the set F = {y | y = a…
- A recent survey found that 54.7% of the population own their homes. In a random sample of 150 heads of households, 92 responded that they owned their homes. At 0.01 level of significance does that indicate a difference from the nation…
- A report stated that the average age of commercial jets in country X is 14 years. An executive of a large airline company selects a sample of 36 planes and finds that the average age of the plane is 11.8 years. The standard deviation …
- The odds of Matthew doing his math homework is 13:7. What is the probability of Matthew doing his homework once in the next two days?
- let x be a random variable with probability density function given by f(x)=(2he^-1/4x ; 0
- FIND THE VALUES FOR EACH OF THE FF. CASES: A. UPPER TAIL AREA OF 0.025 WITH DEGREE OF FREEDOM=28 B. LOWER TAIL AREA OF 0.01WITH DEGREE OF FREEDOM=15 C. WHERE 90% OF THE AREA FALLS BETWEEN THESE TWO t-VALUES WITH df=9
- 2. The owner of a factory that sells a particular bottled fruit juice claims that the average capacity of their product is 250 ml. To test the claim, a consumer group gets a sample of 100 such bottles, calculates the capacity of each …
- A box contains 18 light bulbs. Of these, four are defective. Five bulbs are chosen at random. What is the probability that four are defectives?
- what happens to the variance of the sampling distribution of the sample means when the sample size increases
- The following represent the scores of a group of students on two tests. calculate spearman rs and kendall's tau for these data. Test 1 - 36, 34, 33, 29, 29, 28, 28, 28, 24, 22, 19, 12 Test 2 - 18, 26, 24, 18, 15, 12, 14, 13, 12, 10,…
- The following represent the scores of a group of students on two tests. calculate spearman rs and kendall's tau for these data. Test 1 - 36, 34, 33, 29, 29, 28, 28, 28, 24, 22, 19, 12 and Test 2 - 18, 26, 24, 18, 15, 12, 14, 13, 12, 1…
- Three judges rated eight essays with the following results. Calculate the coefficient of concordance with these data. JUDGE ESSAY 1 2 3 1 8 7 8 2 6 5 6 3 4 6 5 4 1 2 1 5 3 3 2 6 2 1 3 7 5 4 4 8 7 8 7
- The following data represent the operating time in hours for 4 types of pocket calculators before a recharge is required. Use the Kruskal-Wallis test, at the 0.01 level of significance, test the hypothesis that the operating times for…