Arecent survey of 8,000 high school students found that the mean price of a prom dress was $195.00 with a standard deviation of $12.00. alyssa thinks that her school is more fashion conscious and spent more than $195.00. she collected data from 20 people in her high school and found that the average price spent on a prom dress was $208.00. which of the following is the correct z-statistic for this situation?
Big Brain lol
got it right on edge2020
One of the answers is 4.84 and the other is NOT C
Given that Alyssa thinks that her school is more fashion conscious and that students spent more than $195.00. She collected data from 20 people in her high school and found that the average price spent on a prom dress was $208.00.
Since she wants to check whether sample mean x bar is the same as population mean mu = 195
(Right tailed hypothesis test)
The z score can be calculated by the difference of population and sample mean divided by standard error. Standard error can be calculated as the standard deviation divided by square root of sample size From the given the standard error: SE = 12/sqrt (20) = 2.68 Z = (208 -195)/2.68 = 4.85
To calculate the z-statistic, we must first calculate the standard error.
Standard error is standard deviation divided by the square root of the population. In this case, it is equal to 2.68.
The z-score is defined the distance from the sample to the population mean in units of standard error.
z = (195 – 208)/2.68 = -4.86
Hope this helps.