Statistics
posted by monica on .
How do I do this? I am very lost.
If you live in California, the decision to buy earthquake insurance is an important one. A survey revealed that only 133 of 337 randomly selected residences in one California county were protected by earthquake insurance. Calculate the appropriate test statistic to test the hypotheses that at least 40% buy the insurance.

Null hypothesis:
Ho: p = or > .40 >meaning: population proportion is equal to or greater than .40
Alternative hypothesis:
Ha: p < .40 >meaning: population proportion is less than .40
Using a formula for a binomial proportion onesample ztest with your data included, we have:
z = .39  .40 >test value (133/337 = .39) minus population value (.40)
divided by √[(.40)(.60)/337]
Note: .60 = 1  .40
I'll let you finish the calculation.
Hint: Null will not be rejected. You can draw your conclusion from there. 
In a recent survey, 70% of the community favored building a haelth center in their neighborhood. If 14 citizens are chosen, find the probabilty that exactl 6 of them favore the building of the health center.

On your TI84 Calculator Press "2nd" "VARS" for the [Distr] menu. Scroll down to binompdf( and press enter
Then enter in this order
binompdf(14,0.70,6) = 0.023