Proportion and Standard Deviation

1)A barangay captain claims that at least 85% of the residents in his barangay have household pets. To test this claim a researcher randomly selected a sample of 15 residents and find that 5 of them do have pets. What can you conclude at 0.10 level of significance.

2)Consumers know for fact that on valentine's day, the prices of roses vary with an average standard deviation of P75. A random sample of 23 buyers was observed. Their purchasing prices yielded a standard deviation of P87. Can we concluded at the 1% level of significance that the prices of roses on Valentine's day show significant increased variability?

3)An agronomist randomly selected 20 matured calamansi trees of one variety and have a mean height of 10.8ft with standard dev of 1.25ft, while another 12 randomly selected calamansi trees of another variety have a mean height of 9.6ft with standard dev of 1.45ft. Test @ 5% whether the difference of 2 sample standard deviation is significant