Question

1 (b) An electronics company, Sparks Inc., are getting feedback from customers that the battery life of their tablet varies from the advertised 10 hours. (a) The electronics company test 7 batteries at random and record the time it takes them to run from 100% to 0%. The results, in hours, are as follows: (0) 8-4, 8-6, 9-2, 10-3, 8-9, 9-7, 9-3 Find the mean of these battery lives. 9 3 * = 8₁4 + 8₁6 + 6.4.4 92 + (ii) Find the range of these battery lives. 10,3 + 8.9497 4 64,4:7=9_? The researchers tested one more battery and the mean value increased to 9-25 hours. Find the time it takes for this battery to run from 100% to 0%. I w sp puny Допоможіть будь ласка!!

Answer 1

Ответ:

Чтобы найти среднее время автономной работы, мы складываем все сроки службы батареи и делим на количество батарей:

Среднее = (8-4 + 8-6 + 9-2 + 10-3 + 8-9 + 9-7 + 9-3)/7

= 62/7

≈ 8,86 часа

Чтобы найти диапазон, вычитаем наименьшее время автономной работы из самого большого:

Диапазон = наибольшее время автономной работы - наименьшее время автономной работы

= 10-3 - 8-9

= 0,7 часа

Чтобы узнать время автономной работы восьмой батареи, мы используем тот факт, что новое среднее значение составляет 9-25 часов:

(8-4 + 8-6 + 9-2 + 10-3 + 8-9 + 9-7 + 9-3 + х)/8 = 9-25

Умножив обе стороны на 8, получим:

62 + x = 74

Вычитая 62 с обеих сторон, получаем:

x = 12

Поэтому время, необходимое для работы восьмой батареи от 100% до 0%, составляет 12 часов.

Удачи)

Answer 2

To find the mean of the battery lives, you need to sum up all the battery life values and divide it by the number of batteries tested. Let's calculate the mean using the given battery life values:

Battery lives: 8-4, 8-6, 9-2, 10-3, 8-9, 9-7, 9-3

To calculate the mean, add up all the values and divide by the total number of values (which is 7 in this case):

(8-4) + (8-6) + (9-2) + (10-3) + (8-9) + (9-7) + (9-3) = 4 + 2 + 7 + 7 + (-1) + 2 + 6 = 27

Mean = Sum of values / Number of values = 27 / 7 = 3.857 (rounded to three decimal places)

Therefore, the mean battery life is approximately 3.857 hours.

To find the range of the battery lives, you need to subtract the minimum value from the maximum value. In this case, the minimum value is 8-9 and the maximum value is 10-3:

Range = Maximum value - Minimum value = (10-3) - (8-9) = 7 - (-1) = 8

Therefore, the range of the battery lives is 8 hours.

Now, let's move on to the next part of the question. If the mean value increased to 9.25 hours after testing one more battery, we can calculate the battery life of the additional battery.

Let's assume the battery life of the additional battery is x hours.

To calculate the mean with the new battery life included, we need to add the battery life of the additional battery to the sum and divide it by the new total number of values (8 in this case):

(27 + x) / 8 = 9.25

Simplifying the equation:

27 + x = 9.25 * 8 27 + x = 74

Now, solve for x:

x = 74 - 27 x = 47

Therefore, the battery life of the additional battery is 47 hours.