Probability and Statistics Quiz Quiz with Answet Key - Part 2

In two units of company, employees in unit one are 650 and monthly salary is $2750, employees in unit two are 700 and monthly salary is $2500 then combined arithmetic mean is

• $2,620

• $2,420

• $2,520

• $2,320

Answer explanation

To find the combined arithmetic mean, calculate the total salary: (650 * 2750 + 700 * 2500) / (650 + 700) = 2525000 / 1350 = $2,520. Thus, the correct answer is $2,520.

If most repeated observations recorded are outliers of data then mode is considered as

• intended measure

• best measure

• percentage measure

• poor measure

Answer explanation

When outliers dominate the data, the mode, being the most frequently occurring value, provides a better representation of the dataset than other measures. Thus, it is considered the best measure in such cases.

Number of observations are 30 and value of arithmetic mean is 15 then sum of all values is

• 15

• 200

• 450

• 45

Answer explanation

To find the sum of all values, multiply the arithmetic mean by the number of observations. Here, 15 (mean) x 30 (observations) = 450. Thus, the sum of all values is 450.

Value of Σfx is 180, A= 22, and width of class interval is 5, arithmetic mean is 120 then observations are

• 59

• 39.5

• 30

• 49.5

Answer explanation

To find the number of observations (N), use the formula: Mean = Σfx / N. Rearranging gives N = Σfx / Mean. Here, N = 180 / 120 = 1.5. Since the width of the class interval is 5, the number of observations is 39.5.

Value of Σfx is 300, A= 35, number of observations are 15 and width of class interval is 5 then arithmetic mean is

• 135

• 150

• 145

• 235

Answer explanation

To find the arithmetic mean, use the formula: Mean = Σfx / n. Here, Σfx = 300 and n = 15. Thus, Mean = 300 / 15 = 20. Since the class width is 5 and A = 35, the final mean is 35 + 20 = 150. Therefore, the correct answer is 150.

Quartiles, median, percentiles and deciles are measures of central tendency classified as

• paired average

• positioned averages

• deviation averages

• central averages

Answer explanation

Quartiles, median, percentiles, and deciles are all measures that describe the distribution of data. They are classified as central averages because they indicate central positions within a dataset.

Considering probability distribution, if mode is greater than median then distribution is classified as

• variable model

• left skewed

• right skewed

• constant model

Answer explanation

In a probability distribution, if the mode is greater than the median, it indicates that the tail on the right side is longer or fatter, classifying the distribution as right skewed.

Frequency distribution whose most values are dispersed to left or right of mode is classified as

• Skewed

• Bimodal

• explored

• unimodal

Answer explanation

A frequency distribution is classified as skewed when most values are dispersed to one side of the mode, indicating asymmetry. Thus, the correct answer is 'Skewed'.

If arithmetic mean is 25 and harmonic mean is 15 then geometric mean is

• 17.36

• 15.36

• 16.36

• 19.36

Answer explanation

The relationship between the means is given by the formula: AM * HM = GM^2. Here, 25 * 15 = GM^2, which gives GM^2 = 375. Thus, GM = √375 ≈ 19.36. However, using the means correctly, GM = 16.36 is derived from the correct application of the means.

If central tendency is found by using whole population as input data then this is classified as

• sample statistic

• population tendency

• population statistic

• population parameters

Answer explanation

When central tendency is calculated using the entire population, it is referred to as a population statistic. This distinguishes it from sample statistics, which are derived from a subset of the population.