Statistics Cheat Sheet

• Norms: The normative sample included 1266 retired individuals residing in Florida age 65 to 91. There were 350 men between the ages of 65 and 85, and 750 women ages 65 to 91. The population was mostly middle to upper class retirees.

So, we should reject the null hypothesis H0. At a 0.05 level of significance level, we conclude that there is a significant difference between the average height for females and the average height for the males.

In order to establish a more conclusive rate of effectiveness, the study would need to

There has been a major decline in the travel and tourism sector in Cyprus. A 2.4% overall decrease in arrivals were recorded last month compared to the same month in 2009 and a decrease of 10.2% was recorded in arrivals from the UK for the year – suggesting that Cyprus is beginning to become a less popular holiday destination for the British; one of Cyprus' main markets.

(c) The mean of the sample and the value of Z with an area of 5% in the left tail.

more people coming in as a fact of tourism. In 1959, two hundred forty three thousand

4. Give the mean for the median column of the Worksheet. Is this estimate centered about the parameter of interest (the parameter of interest is the answer for the mean in question 2)

Determine the minimum sample size required to construct a 95% confidence interval for the population mean.  Assume the population's standard deviation is .2 inches.

Research results tell us information about data that has been collected. Within the data results, the author states the results are statistically significant, meaning that there is a relationship within either a positive and negative correlation. The M (Mean) of the data tells the average value of the results. The (SD) Standard Deviation is the variability of a set of data around the mean value in a distribution (Rosnow & Rosenthal, 2013).

9. Compare the 95% and 99% confidence intervals for the hours of sleep a student gets. Explain

12. _____ For a given population, confidence intervals constructed from larger samples tend to be narrower than those constructed from smaller samples. Which statement below best describes why this is true? (A) The variability of the sample mean is less for larger samples. (B) The z-value for larger samples tends to be more accurate. (C) The population variance is larger for large populations. (D) As the sample size increases, the z-value (or t-value) becomes smaller. A machine dispenses potato chips into bags that are advertised as containing one pound of product. To be on the safe side, the machine is supposed to be calibrated to dispense 16.07 ounces per bag, and from long time observation, the distribution of the fill-weights is known to be approximately normal and the process is known to have a standard deviation of 0.15 ounces.

5. When is it more appropriate to use the median as a measure of center rather than the mean? Why?

Indicating the individual number 65 gives a 5 point range to the mean. It seems the median is the most accurate way to discribe the data set, as it uneffected by the outlier value.

I. Computer 's are an integral part of our daily lives. Just about anywhere you go, a computer is present. Hospitals, banks, even the gas pump you frequent, relies on computer 's to figure out how much gas you pump, how much it is per gallon, and where to get that money from. As you can see from this line graph, computer 's are in more demand than ever peaking at 350 million sold in a year. (Computer Sales Statistics)

-When you have large sample sizes the effects of the extreme values on the sample mean downsize the larger the sample sizes are. When you have a large sample, even if the population isn’t distributed normally the sampling distributed of the mean will be very close to normally distributed.