No verified paper has been uploaded for AJKPSC-PMS Statistics Set-9 yet.
The MCQs below are drawn from the Statistics subject category.
Showing 1121–1130
of 1558 MCQs
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1121
Calculate the arithmetic mean of the following test scores for 20 students: 10, 11, 12, 12.5, 13.5, 14, 10, 11, 12, 12.5, 13.5, 14, 8, 9, 9, 8, 10, 11, 11.5, 12.5.
To find the arithmetic mean, sum all the given values and divide by the total number of observations (20). The sum of these 20 scores is 225. Dividing 225 by 20 yields 11.25, which represents the average performance of the class on the test.
1122
In a perfectly symmetrical distribution, what is the relationship between the mean and the mode?
For any perfectly symmetrical unimodal distribution, the mean, median, and mode are identical. This occurs because the distribution is balanced around the center point, meaning the arithmetic average (mean), the middle value (median), and the most frequent value (mode) all coincide at the same central location.
1123
What term describes the middle value of a data set when the observations are arranged in ascending or descending order?
The median is defined as the positional average that divides a sorted data set into two equal halves. It is the value that occupies the central position in an ordered array, ensuring that 50% of the observations fall below it and 50% fall above it.
1124
What is the property that the sum of the first power of deviations from the arithmetic mean is zero?
The sum of deviations of all observations from their arithmetic mean is always zero. This is a mathematical property of the mean. The provided answer 'Normal' is likely a misclassification in the source, but we preserve the key while noting the property.
1125
Identify the mode of the following dataset: 2, 4, 6, 6, 6, 8.
The mode is the value that appears with the highest frequency in a dataset. In the provided set {2, 4, 6, 6, 6, 8}, the number 6 appears three times, while the other numbers appear only once. Therefore, 6 is the mode.
1126
Which branch of statistics focuses on the collection, presentation, and analysis of data?
Descriptive statistics is the branch of statistics concerned with summarizing, organizing, and presenting data in a meaningful way. It utilizes tools such as frequency distributions, measures of central tendency, and graphical displays to describe the main features of a dataset without attempting to make inferences about a larger population.
1127
What is the Geometric Mean of the dataset containing the values -2, 4, 3, 6, and 0?
The geometric mean is defined as the n-th root of the product of n numbers. If any value in the dataset is zero, the product becomes zero, and if negative values are present, the geometric mean is undefined in the real number system. Thus, it cannot be computed for this specific set.
1128
Given Σfd = 165, assumed mean (A) = 25, class width (h) = 10, and arithmetic mean = 145, what is the total number of observations (N)?
Using the formula for the mean in grouped data: Mean = A + (Σfd / N) * h. Substituting the given values: 145 = 25 + (165 / N) * 10. Subtracting 25 gives 120 = (1650 / N). Solving for N: N = 1650 / 120 = 13.75. The provided answer 36 appears inconsistent with the calculation. The answer key is preserved as requested.
1129
From which measure of central tendency is the sum of deviations of observations always equal to zero?
A fundamental property of the arithmetic mean is that the sum of the differences between each data point and the mean is zero. Mathematically, the sum of (xi - x_bar) equals zero because the positive and negative deviations cancel each other out exactly.
1130
Which notation is used to represent the sample mean in statistics?
In statistical notation, it is standard practice to use Roman letters (like x-bar) to represent sample statistics, which are estimates of population parameters. Conversely, Greek letters (like μ for the population mean) are reserved for population parameters. Therefore, x̅ is the correct symbol for the sample mean.
