Answer: This is what Khan Academy said the answer was
Answer:
20%
Step-by-step explanation:2.8-3.5 then divide that by 3.5 and multiple the answer by 100 to get the percent
Answer:
January had a higher z-score for sales on the 15th, and the value of that z-score was of 0.5.
Step-by-step explanation:
z-score:
In a set with mean
and standard deviation
, the z-score of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
January:
The mean daily sales for January was $300 with a standard deviation of $20. On the 15th of January, the shop sold $310 of yogurt. This means, respectively, that
. So



February:
The mean daily sales for February was $320 with a standard deviation of $50. On the 15th of February, the shop sold $340 of yogurt. This means, respectively, that
. So



January had a higher z-score for sales on the 15th, and the value of that z-score was of 0.5.
Assuming that am supposed to calculate the the mean absolute deviation of
1,2,3,4,5,6,7
mean absolute deviation is calculated by first calculating the mean;
(1+2+3+4+5+6+7) =28/7
= 4
Then, find the absolute value (the difference between each value in the data and the mean) (x-μ)
= -3,-2,-1,0,1,2,3
Absolute values= 3,2,1,0,1,2,3
Then we find the mean of the values,
3+2+1+0+1+2+3 = 12
= 12/7
= 1.7143
Therefore, the mean is 4, and the Mean absolute deviation is 1.7143