Answer:
The upper bound is 399.5
Step-by-step explanation:
Let's start by calculating the mean value of the distribution as the addition of all values given divided by 12:
Average = 289.75.
If the standard deviation is 56, then the upper bound in 95% the confidence interval for the mean price of the phones is going to be given by the mean value added to 56 times 1.96 (since 95% of the population is withing 1.96 times the standard deviation)
That is: 289.75 + 56 * 1.96 = 399.51
which rounded to one decimal place gives: 399.5
3a- 2b + 8b - 2 + 6a + 3c
3a + 6a -2b +8b + 3c - 2
9a + 6b + 3c - 2
Answer:9.9
Step-by-step explanation:
Add up the scores and dividing the total by the number of scores.