0000:00:00:00:00Start7Number 7ExplanationThe average mathematics exam score of 393939 students is 454545. If Yanto's score is combined with that group, the average score becomes 464646. Then Yanto's exam score is ....474747515151858585909090929292ExplanationWe use the concept of the mean (average) value (xˉ\bar{x}xˉ), which is defined as the sum of all data values (Σx\Sigma xΣx) divided by the number of data points (nnn). Initial Condition Initially, there are 393939 students with an average score of 454545. Their total score is: Σx1=xˉ1⋅n1\Sigma x_1 = \bar{x}_1 \cdot n_1Σx1=xˉ1⋅n1Σx1=45×39=1755\Sigma x_1 = 45 \times 39 = 1755Σx1=45×39=1755 After Yanto Joins When Yanto joins, the number of students increases to n2=39+1=40n_2 = 39 + 1 = 40n2=39+1=40. The new class average becomes 464646. The new total score is: Σx2=xˉ2⋅n2\Sigma x_2 = \bar{x}_2 \cdot n_2Σx2=xˉ2⋅n2Σx2=46×40=1840\Sigma x_2 = 46 \times 40 = 1840Σx2=46×40=1840 Finding Yanto's Score Yanto's score (YYY) is the difference between the new total score and the initial total score. Y=Σx2−Σx1Y = \Sigma x_2 - \Sigma x_1Y=Σx2−Σx1Y=1840−1755Y = 1840 - 1755Y=1840−1755Y=85Y = 85Y=85 Thus, Yanto's exam score is 858585.
7Number 7ExplanationThe average mathematics exam score of 393939 students is 454545. If Yanto's score is combined with that group, the average score becomes 464646. Then Yanto's exam score is ....474747515151858585909090929292ExplanationWe use the concept of the mean (average) value (xˉ\bar{x}xˉ), which is defined as the sum of all data values (Σx\Sigma xΣx) divided by the number of data points (nnn). Initial Condition Initially, there are 393939 students with an average score of 454545. Their total score is: Σx1=xˉ1⋅n1\Sigma x_1 = \bar{x}_1 \cdot n_1Σx1=xˉ1⋅n1Σx1=45×39=1755\Sigma x_1 = 45 \times 39 = 1755Σx1=45×39=1755 After Yanto Joins When Yanto joins, the number of students increases to n2=39+1=40n_2 = 39 + 1 = 40n2=39+1=40. The new class average becomes 464646. The new total score is: Σx2=xˉ2⋅n2\Sigma x_2 = \bar{x}_2 \cdot n_2Σx2=xˉ2⋅n2Σx2=46×40=1840\Sigma x_2 = 46 \times 40 = 1840Σx2=46×40=1840 Finding Yanto's Score Yanto's score (YYY) is the difference between the new total score and the initial total score. Y=Σx2−Σx1Y = \Sigma x_2 - \Sigma x_1Y=Σx2−Σx1Y=1840−1755Y = 1840 - 1755Y=1840−1755Y=85Y = 85Y=85 Thus, Yanto's exam score is 858585.
