Question

the table below shows the number of days it rained each month.
month rainy days
march 14
april 18
may 15
june 10
july 8
august 9

1. what is the mean of this data, rounded to the nearest tenth?
2. how does the mean change if junes data is removed? (shade in the correct answer)

a the mean of the data increases.
b the mean of the data stays the same.
c the mean of the data decreases.

Explanation:

Step1: Calculate sum of all data

$14 + 18+15 + 10+8 + 9=74$

Step2: Calculate number of data points

There are 6 data - points.

Step3: Calculate the mean

The mean $\bar{x}=\frac{74}{6}\approx12.3$

Step4: Remove June's data and calculate new sum

New sum $=74 - 10=64$

Step5: Calculate new number of data points

New number of data - points is 5.

Step6: Calculate new mean

New mean $\bar{y}=\frac{64}{5}=12.8$

Step7: Compare the means

Since $12.8>12.3$, the mean increases.

Answer:

1. $12.3$
2. A. The mean of the data increases.