Stats Help for College-level Students

Testing the claim.

A company claims that the weight of the cereal in one of its packages is at least 14 oz. Eight packages are tested and the weights given below are measured. Test the claim at a = 0.01. 14.6, 13.8, 14.1, 13.7, 14.0, 14.4, 13.6, 14.2

Finding Minimum Sample Size

A survey of shoppers is planned to determine what percentage use credit cards. Prior surveys suggest that 59% use credit cards. The required margin of error is 0.02 at 95% confidence. What is the minimum sample size required to assure that your sample proportion "p" will be within the required margin of error, around the popul ...continues

Understanding how to calculate statistical significance.

How do I calculate statistical significance. I conducted an observation in a classroom (1/2 per day (specific time), 5 consecutive days, 12 students in class) to determine the number of times a specific target behaviour occurred (frequency count). The following week I observed one specific student in the class (1/2 hour per ...continues

Calculating mean, median, variance and standard deviation from a sample population.

In a recent survey of small bakeries in the Southeast, 10 bakeries report the following number of employees: 15, 14, 12, 19, 13, 14, 15, 18, 13, 19. Find the mean, median, variance and standard deviation.

Trials and probability

1. What is the probability that it rained on a particular day, given that it rained on the previous day? 2. What is the probability that it rained on a particular day , given that it did not rain on the previous day? 1. Collect the data, citing your source and time span you used 2. Find p-hat(R), the proportion of days o ...continues

Determining the probability using binomial distribution.

The Bell telephone co. surveyed an apartment building with 500 units to find out who subscribes to their service. Turns out 70% of the units use Bell's service. Find the probability that less than 340 units are using Bell services so we are looking for: P(X<340) Z= 340-350/10.25=-0.98

Family incomes in two particular neighborhoods follow a normal distribution.

QUESTION: Example: Family incomes in two particular neighborhoods follow a normal distribution. For Neighborhood 1 the mean is $26,500, with a standard deviation of $15,000. For Neighborhood 2, the mean is $30,000 with a standard deviation of $18,000. A) What proportion of families in Neighborhood 1 have incomes below the ...continues

Understanding and calculating probability distribution.

A researcher is studying IQ levels. From past experience she knows the population mean IQ for adults is 110 and the standard deviation is 15. a) If samples of 30 IQs are selected and the sample mean is calculated for each sample, what can be said about the sampling distribution of the sample means, and why? b) If she ta ...continues

STATISTICAL TERMS

Can you explain the primary difference between using the Generalized Difference Equation and First Difference Method in correcting for serial autocorrelation? These are methods used in a multiple regression analysis that will compensate for serial autocorrelation (time series data). I guess my question is a distinction between ...continues

Probabilities

What is Binomial Expansion?