# Practice Questions for Business Statistics

Topics: Normal distribution, Chi-square distribution, Standard deviation Pages: 3 (453 words) Published: April 23, 2013
a. Is it reasonable that the distribution of checking account balances approximates a normal distribution? Yes. Its reasonable because the sample size is large and and n -( increases the distribution of checking account balances approximates normal distribution.

b. Determine the mean and the standard deviation for the sample of 60 customers.

|Mean = |1516.667 |
|Variance= |2637500 |
|Std dev= |1624.038 |

c. Compare the actual distribution with the theoretical distribution.

|Class Interval |Actual Distribution |Theoretical Distribution | |0-500 |4 |2 | |500-1000 |7 |9 | |1000-1500 |15 |19 | |1500-2000 |22 |18 | |2000-2500 |11 |9 | |2500-3000 |1 |3 |

d. Cite some specific examples and comment on your findings. |Class Interval |Observed Frequency |Actual frequency | |60-65 |3 |3 | |65-70 |21 |31 | |70-75 |150 |148 | |75-80 |335 |322 | |80-85 |326 |319 | |85-90 |135 |144 | |90-95 |26 |30 | |95-100 |4 |3 | | |...