Refer to the following frequency distributionfor Questions 2

Refer to the following frequency distributionfor Questions 2, 3, 4, and 5.Show all work. Just the answer, without supporting work, will receive no credit.

The frequency distributionbelow shows the distribution for checkout time (in minutes) in UMUC MiniMart between 3:00 and 4:00 PM on a Friday afternoon.

2. Complete the frequency table with frequency and relative frequency.Express the relative

frequency to two decimal places.

3.What percentage of the checkout times was at least 3 minutes?

4.In what class interval must the median lie? Explain your answer.

5.Does this distribution havepositive

skew or negative skew? Why?

Solution

2.

(Using Relative frequency = Frequecy / 25

and, Sum of frequencies = 25)

3. percentage of the checkout times was at least 3 minutes = Sum of relative frequencies of time > 3 minutes

= 0.20 + 0.12 + 0.08 = 0.40

= 40%

4. Median will lie at the point of cumulative frequency being 0.50

So It will lie in the interval 2.0-2.9 as the cumulative frequency of this interval is 0.60 and of the previous interval is 0.12, so 0.50 lies within this interval.

5. Observations are concentrated at the beginning, that is initial intervals have higher relative frequency, so the distribution is positively skewed.