Answer:
No. The data in this study were not based on a random method. This is a key requirement for an inference to be made from the two-sample t-test.
Step-by-step explanation:
1. Hayden can use the two-sample t-test (also known as the independent samples t-test)to find out if there was a difference in the time spent in the checkout time between two grocery stores and to conclude whether the difference in the average checkout time between the two stores is really significant or if the difference is due to a random chance. There are three conditions to be met when using the two-sample t-test.
2. The first condition is that the sampling method must be random. This requirement was not met in this study. Each customer from each store should have an equal chance of being selected for the study. This was not achieved.
3. The distributions of the sample data are approximately normal. This is achieved with a large sample size of 30 customers selected for each study.
4. The last but not the least condition is the independence of the sample data. Sample data here is independent for both samples.
Answer:
10
Step-by-step explanation:
2+(2x4)
2x4=8
2+8=10
<span>In statistics finding percentiles relates to the standard deviation and something called a z-score. For normally distributed data the z-score represents how many standard deviations above or below the mean that group is a part of. The z-score for normally distributed data for the 90th percentile is 1.28. The standard deviation is then multiplied by the z-score to find, in this case, the shotlrtest height needed to be in the 90th percentile of this population. In this case to be in the 90th percentile your height must be 60.27 inches.</span>
