Retailers of collectible postage stamps often buy their stamps in large quantities by weight at auctions. The prices the retailers are willing to pay depend on how old the postage stamps are. Many collectible postage stamps at auctions are described by the proportions of stamps issued at various periods in the past. Generally the older the stamps the higher the value. At one particular auction, a lot of collectible stamps is advertised to have the age distribution given in the table provided. A retail buyer took a sample of 73 stamps from the lot and sorted them by age. The results are given in the table provided. Test, at the 5% level of significance, whether there is sufficient evidence in the data to conclude that the age distribution of the lot is different from what was claimed by the seller.
|
Year
|
Claimed Distribution
|
Observed Frequency
|
|
Before 1940
|
0.10
|
6
|
|
1940 to 1959
|
0.25
|
15
|
|
1960 to 1979
|
0.45
|
30
|
|
After 1979
|
0.20
|
22
|