Question

The accompanying frequency distribution of fracture strength (MPa) observations for ceramic bars fired in a particular kiln appeared in an article.

Class	81–<83	83–<85	85–<87	87–<89	89–<91	91–<93	93–<95	95–<97	97–<99
Frequency	6	7	18	30	43	27	22	12	3

a) construct a histogram

Comment on any interesting features. which one is the correct statement  

A representative value for this data would be around 83 MPa. The histogram shows strong positive skewness and is unimodal ?

.A representative value for this data would be around 90 MPa. The histogram is reasonably symmetric and unimodal. ?

A representative value for this data would be around 95 MPa. The histogram is reasonably symmetric and unimodal.?

A representative value for this data would be around 95 MPa. The histogram shows strong negative skewness and is unimodal. ?

A representative value for this data would be around 95 MPa. The histogram shows strong positive skewness and is unimodal. ?

(b)

What proportion of the strength observations are at least 85? Less than 95? (Round your answers to four decimal places.)

at least 85less than 95

(c)

Roughly what proportion of the observations are less than 90? (Round your answer to four decimal places.)

Answer 1