Again, we assume that the (theoretical) population mean is 4, the sample mean is 5.0, and the sample standard deviation s is 1.936. Now, the standard error will be When N = 20, the critical value for a 5% significance test will be 2.09 (because the t-distribution curve is closer to the normal distribution). Why the t-distribution is a family of curves. 2  How critical t-values change as a function of the alternative hypothesis and the Type I error rate. 3  How to calculate t-values for a single sample t-test, an independent samples t-test, and a paired t-test.
The 805 Area Code (or Area Code 805) is located in the state of CA. Area Code 805 is one of the 269 3-digit telephone area codes in the USA.ry searching for any 805 Area Code phone number today, and discover what Spokeo can do for you. Top Cities. Oxnard, Arroyo Grande, Cambria, Simi Valley, Ventura, Thousand Oaks, Paso Robles, Newbury Park, San Luis Obispo and Guadalupe.
More About Area Code 804 Area code 804 was first put in service June 24, 1973. In 1996, area code 804 was split, and some of the phone numbers had to be updated to area code 757 on that date. In 2001, area code 804 was split, and some of the phone numbers had to be updated to area code 434 on that date. To avoid exhausting all possible phone numbers in this area code, relief planning has begun. Currently, the largest city it serves is Richmond, VA, and it overlaps coverage areas with area code . Overview of Active Prefixes