Kristel Kaye Basas
11-ABM Alfonso
Formulate the null and alternative hypotheses. Identify whether it is one-tailed or two-tailed. If the hypothesis is
One-tailed, identify its direction whether it is left or right. Write your answer on a separate sheet of paper.
1. The average salary of an accountant is ₱24,620 per month in the Philippines.
Ho: ___ μ = ₱ 24,620___ Ha: __ μ ≠ ₱ 24,620__ ___two-tailed test
2. A normal smartphone battery manufacturer claims that the mean life of a certain type of battery is more
than 650 hours.
Ho: __ μ_≤ 650 or μ = 650 ___ Ha: ___ μ > 650____ ___right-tailed test
3. According to an international shipping company, a package from US can arrive to Manila in an average of
less than 8 business days.
Ho: _ μ ≥_8 or μ_=_8__ Ha: _ μ ˂ 8_____ __left-tailed test
4. The average price of a certain type of car is greater than ₱600,000.
Ho: _ μ ≤ ₱600,000 or μ = ₱600,000_____ Ha: _ μ > ₱600,000__ __right-tailed test
5. A research organization reports that the mean of adult grocery shoppers who never buy the store brand in
Metro Manila is 300.
Ho: _ μ = 300___ Ha: _ μ ≠_300__ ___two-tailed test
6. A study claims that the mean survival period for certain cancer patients treated immediately with
chemotherapy and radiation is 24 months.
Ho: _ μ = 24___ Ha: _ μ ≠_24____ __two-tailed test
7. The average pre-school cost for tuition fees last year was ₱ 15,500. The following year, 20 schools had a
mean of ₱ 13, 100 and standard deviation of ₱ 2,500.
Ho: _ μ = ₱15,500____ Ha: _ μ ≠_₱15,500____ __two-tailed test
8. A magazine reports that a typical shopper spends less than 10 minutes in line waiting to check out. A
sample of 30 shoppers at the DM Supermarket showed mean of 9.5 minutes with standard deviation of
2.7 minutes.
Ho: _ μ ≥_10 or μ = 10___ Ha: _ μ < 10____ ___left-tailed test
9. The principal of Mabundok High School claims that the students in his school have above average
intelligence. Arandom sample of 30 students’ IQ scores have a mean score of 113. The mean population
IQ is 100 with a standard deviation of 15. Is there an evidence to support his claim?
Ho: _ μ = 100___ Ha: _ μ >_100____ __right-tailed test
10. The owner of BYD manufacturer claims that their batteries last an average of at most 350 hours under
normal use. A researcher randomly selected 20 batteries from the production line and tested them. The
tested batteries had a mean life span of 270 hours with a standard deviation of 50 hours.
Ho: _ μ ≤_350 or μ = 350____ Ha: _ μ >_350____ __right-tailed test
