Using the mean concept, it is found that we will need 15 more points to bring up his average up to 90%.
The mean of a data-set is the <u>sum of all observations divided by the number of observations</u>.
In this problem:
- In the first 5 observations, total of 21 out of 25 points, hence the mean for these observations is
. - In the next n observations, mean of 1.
Hence, the mean is:
We want the mean to be of 0.9, thus:
3 more testes are need, each worth 5 points, hence, 15 more points are needed to bring up his average up to 90%.
A similar problem is given at brainly.com/question/25323941
60 min = one hour
1/3 *60 =20 mins
= 20/2
= 10 min
Lisa has ten minutes
Answer and explanation:
Given : The demand for a product for the last six years has been 15, 15, 17, 18, 20, and 19. The manager wants to predict the demand for this time series using the following simple linear trend equation : 
To find : What are the forecast errors for the 5th and 6th years?
Solution :
Data : 15, 15, 17, 18, 20, and 19.
The simple linear trend equation is given as,
For t = 5 years
Observed 
Predicted
Forecast error = Observed – Predicted = 20 – 22 = -2
Absolute forecast error = |-2| = 2
.
For t = 6 years
Observed 
Predicted
Forecast error = Observed – Predicted = 19 – 24 = -5
Absolute forecast error = |-5| = 5.
