Answer:
The correct options are (c) and (d).
Step-by-step explanation:
The assumptions made before using a t-distribution for a hypothesis test are:
- The scale of the data should be continuous or ordinal.
- The sample selected should be a simple random sample.
- The data selected should follow a normal distribution or form a bell-shaped curve when plotted.
- The sample selected must be large enough so that when plotted a normal distribution curve is formed.
- Homogeneous variance exists so that the standard deviations of the samples are approximately equal.
A sample size of 5 a sample size of 50 sample will not be accurate for a t-test because on of the sample size is, 5.
This sample size is very small and when plotted will not follow a normal distribution.
The sets that differed in variance will not be accurate for a t-test because for using a t-test homogeneity of variances is assumed.
Thus, the correct options are (c) and (d).