selecting random samples

A survey reported that 70% of college students aged 18 to 26 own a cell phone. To test this report a professor selected a random sample of 150 college students and found that 100 own a cell phone. Is the sample report differs from population report at α..

In a batch of 5,000 wrist watches, there are on an average 10 defective ones. If a random sample of 500 is selected, then what is the probability of two defective ones? => 0.27 or 0.36 or 0.184 or 1.35..

Choose the incorrect statement(s). I. A statistic is a numeric descriptive measure of a population. II. The sampling error is the difference between the population value of interest and sample value. III. If the sample is randomly selected from the ..

In a survey it was found that 20% of people living in a society watch channel A. If a random sample of 10 people is selected, then find the probability that exactly 5 people in the sample watch channel A. => 0.5 or 0.2 or 0.026 or 0.26..

In a survey it was found that 20% of people living in a society watch channel A. If a random sample of 10 people are selected, then find the probability that at least 3 people in the sample watch channel A. => 0.59 or 0.3 or 0.2 or 0.323..

The average price for different configurations of laptops in a shop is $1,300. Assume the standard deviation is $300. If a random sample of 9 laptops is selected, then find the probability that the mean of the sample will be less than $1,000. => 0.13% or 49.8..

The manager of the local branch of a savings bank has determined that 30% of all depositors have multiple accounts at the bank. If a random sample of 200 depositors was selected, what is the probability that sample proportion of depositors will be between 0.3..

A manufacturer of incandescent bulbs claims that the average life time of a bulb is more than 1,000 hours with a standard deviation of 1.6 hours. The inspection department selected a random sample of 36 incandescent bulbs and found their average life time as 1,001.50 h..

The probability that a student has access to Internet from his/her home is 40%. If a random sample of 100 students is selected, then find the probability that between 50% and 60% of the students have access to Internet from their home. => 2.61% or 0.026% or 97.39% or 2..

In a class, 50% of the students play basketball, 30% study, and 20% will go to a movie on the weekends. If a sample of 5 students are randomly selected, then find the probability that three play basketball, one studies and one will go to a movie. => 0.15 or 0.6 or 0.05..