Β A hardware manufacturer produces bolts used to assemble various machines. Assume that the diameter of bolts produced by this manufacturer has an unknown population mean π and the standard deviation is 0.1 mm. suppose the average diameter of a simple random sample of 50 bolts is 5.11 mm. (a) Calculate the margin of error of a 95% confidence interval for π.
A school wants to know the proportion of students who choose online classes as their mode of learning with 90% confidence. The first survey showed that 75% choose online classes as their mode of learning. The school wants to be accurate within 3% of the true proportion. What is the total number of sample size?
The average weight of 25 chocolate bars selected from a normally distributed population is 200 g with a standard deviation of 10 g. Find the interval estimate using 98% confidence level.
a. That the teacher owes at least 6,740
b. that the teacher owes more than 19270
c. that the teacher owes between 6740 and 19270
What is a method of sampling in which every member of the population has an equal probability of being chosen?
The average height of a random sample of 400 people from San Pablo City is 1.75m. It is known that the heights of the population are random variables that follow a normal distribution with a variance of 0.16. Determine the interval of 99% confidence for the average heights of the population.Β
The owner of a restaurant that serves continental food wants to study characteristics of his customers. He decides to focus on two variables: the amount of money spent by customers and whether customers order dessert. The results from a sample of 60 customers are as follows:
β’ Amount spent ( =$38.54, S= $7.26)
β’ 18 customers purchased dessert.
Construct a 95% confidence interval estimate of the population mean amount spent per customer in the restaurant. _____________
Construct a 90% confidence interval estimate of the population proportion of customers who purchase dessert
The prevalence of a certain type of cancer among men aged 55βππ is 1 in 100. A blood test will be positive 95% of the time if the cancer is present but it is also positive 4% of the time if the cancer is not present. 2.1. In a routine checkup, 56-year-old men receive a positive blood test. What is the probability that he has the type of cancer? 2.2. What is the probability that a randomly selected 56-year-old men tests negative?
In a given normal distribution, the population mean is 80 and the population standard deviation is 2.5. Find the corresponding standard z β score of the following values.
The population of each classroom for face-to-face classes consists of the numbers 10, 11, 15, and 9. List all the sample size of 3 from this population and compute the mean of each sample.