Question

The data set below provides the monthly rent (in dollars) paid by 7
tenants.
990,879,940,1010,950,920,1430

Suppose the rent for one of the tenants changes from $1430
to $1115
What is the mean before the rent changes?
A.Before the rent change, the mean was $990
. After the rent change, the mean becomes $963

B.Before the rent change, the mean was $1017
. After the rent change, the mean becomes $936

C. Before the rent changes, the mean is $1017
. After the rent changes, the mean is $972
Best answer

.

Answer 1

To find the means before and after the rent change, we first need to calculate the mean of the original data set and then compute the mean after replacing the $1430 rent with $1115.

### Step 1: Calculate the mean before the rent change

The original rent values are:

990, 879, 940, 1010, 950, 920, 1430

#### Calculate the sum of the original rents:

\[
\text{Sum} = 990 + 879 + 940 + 1010 + 950 + 920 + 1430 = 8190
\]

#### Calculate the mean:

\[
\text{Mean} = \frac{\text{Sum}}{\text{Number of tenants}} = \frac{8190}{7} \approx 1170
\]

### Step 2: Change the rent from $1430 to $1115

Now, replace $1430 with $1115 and compute the new sum:

\[
\text{New Sum} = 990 + 879 + 940 + 1010 + 950 + 920 + 1115 = 6814
\]

### Step 3: Calculate the mean after the rent change:

\[
\text{New Mean} = \frac{\text{New Sum}}{\text{Number of tenants}} = \frac{6814}{7} \approx 974
\]

### Summary of results:

- Before the rent change, the mean rent was approximately **1170**.
- After the rent change, the mean rent was approximately **974**.

### Conclusion

Looking at the options provided, we find:

A. Before the rent change, the mean was $990. After the rent change, the mean becomes $963

B. Before the rent change, the mean was $1017. After the rent change, the mean becomes $936

C. Before the rent changes, the mean is $1017. After the rent changes, the mean is $972.

None of the options provided are correct based on our calculations, but option **C** gets closer to what we computed after "973" however, it is still slightly off.

So the mean before the rent change is actually approximately **1170**, and after it is approximately **974**. If you want the option that is closest to a reasonable approximation based on your question, **C** is the closest.