Exam 7: Continuous Probabilitydistributions

Alpha Corporation receives a shipment of flour every morning from their supplier. The flour is in 40 Kg bags and Alpha will reject any shipment that is more than 5% underweight. The foreman samples 35 bags with each shipment and if the bags average more than 5% underweight, the whole Shipment is returned to the supplier. Determine the value for the standard error of the proportion.

(i. The type of sampling when a population is first divided into subgroups and then a sample is Selected from each subgroup is called stratified random sampling. (ii. Auditors may select every 20th file starting with say, the 5th file in the top drawer. Then file Numbers 25, 45, 65, 85,... are audited. This type of sampling is called systematic sampling. (iii) The mean of a population is called a parameter.

The Intelligence Quotient (IQ) test scores are normally distributed with a mean of 100 and a Standard deviation of 15. i. What is the probability that a person would score 130 or more on the test? ii. You enrolled in a class of 25 students. What is the probability that the class' average IQ exceeds 130?

A convenience store estimates that 25% of its customers come in to buy milk. What is the Probability that out of the next 200 customers, 60 or fewer will buy milk?

Sampling error is the difference between a corresponding sample statistic and the

Suppose we select every fifth invoice in a file. What type of sampling is this?

A province-wide sample survey is to be made. First, the province is subdivided into counties. Seven Counties are selected at random and further sampling is concentrated on these seven counties. What type of sampling is this?

All possible samples of size n are selected from a population and the mean of each sample is Determined. What is the mean of the sample means?

Alpha Corporation receives a shipment of flour every morning from their supplier. The flour is in 40 Kg bags and Alpha will reject any shipment that is more than 4% underweight. The foreman samples 40 bags with each shipment and if the bags average more than 4% underweight, the whole Shipment is returned to the supplier. Determine the value for the standard error of the proportion.

Alpha Corporation receives a shipment of flour every morning from their supplier. The flour is in 40 Kg bags and Alpha will reject any shipment that is more than 4% underweight. The foreman samples 60 bags with each shipment and if the bags average more than 4% underweight, the whole Shipment is returned to the supplier. Determine the value for the standard error of the proportion.

(i. As the sample size (n) increases, the spread in the distribution of the sample means increases. (ii. If the sampling size equals the population size, the sampling error is zero. (iii) If a population is normally distributed, the sampling distribution of the mean is normally Distributed.

(i. As the sample size (n) increases, the spread in the distribution of the sample means stays the Same. (ii. If the sampling size equals the population size, the sampling error is 1. (iii) If a population is normally distributed, the sampling distribution of the mean is normally Distributed.

(i. The type of sampling when a population is first divided into subgroups and then a sample is Selected from each subgroup is called stratified random sampling. (ii. Auditors may select every 20th file starting with say, the 5th file in the top drawer. Then file Numbers 25, 45, 65, 85,... are audited. This type of sampling is called cluster sampling. (iii) The mean of a population is called a parameter.

Dawson's Repair Service orders parts from an electronic company who advertises its parts o be no More than 2% defective. What is the probability that Bill Dawson finds 3 or more parts out of a Sample of 60 to be defective?

A study of a company's practice regarding the payment of invoices revealed that on the average an Invoice was paid 20 days after it was received. The standard deviation equalled five days. A sample Of 25 invoices is selected. Assuming that the distribution is normal, what percent of the sampled Invoices were paid within 15 days of receipt?

Alpha Corporation receives a shipment of flour every morning from their supplier. The flour is in 40 Kg bags and Alpha will reject any shipment that is more than 5% underweight. The foreman samples 50 bags with each shipment and if the bags average more than 5% underweight, the whole Shipment is returned to the supplier. Determine the value for the standard error of the proportion.

The daily sales of a small retail store in Toronto for the last 365 days are normally distributed with a Mean of $2,050, and a standard deviation of $300. i. What is the probability of daily sales exceeding $2,500? ii. From a sample of 49 days, what is the probability of having a sample mean less than $2,500?

What is the difference between a sample mean and the population mean called?

Prince Edward Island Fisheries and Environment has been feeding a special food to rainbow trout fingerlings in a pond. A sample of the weights of 40 trout revealed that the mean weight is 402.7 Grams and the standard deviation 8.8 grams. What is the probability that the mean weight for a Sample of 40 trout exceeds 405.5 grams?

A new extended-life light bulb has an average service life of 750 hours, with a standard deviation of 50 hours. The shape of this distribution is unknown. From a sample of 100 light bulbs, about what Percent of the bulbs will last more than 700 hours?