t - test

A research was conducted to find out the effect of plant extract X concentration as mosquito larvicide. The following data were gathered. 

Table A: Mortality of larvae within 24 h

Dishes	20% extract	50% extract
1	17	15
2	18	18
3	17	19
4	15	19
5	19	20
6	20	18
7	18	17
8	18	15
9	19	18
10	17	17

Hypotheses:

H₀ : Mean of Mortality in 20% extract = Mean of Mortality in 50% extract

H₁:  Mean of Mortality in 20% extract ≠ Mean of Mortality in 50% extract


Level of Significance: 0.05

Solving for T value (Results given)

Table 1. Group Statistics

larvae mortality	extract concentration	N	Mean	Std. Deviation
	20% extract	10	17.8000	1.39841
	50% extract	10	17.6000	1.64655

Table 2. Independent Samples Test

larvae mortality	Sig.	t-test for Equality of Means t	df		Mean Difference	Std. Error Difference
	.561	.293	18		.2000	.68313

Table 1 shows the group statistics of the scores obtained. It can be seen that the mean mortality are 17.8 and 17.6 in 20% and 50% extracts, respectively.

Table 2 shows the results of independent sample t-test.  the t - value of 0.293 having a significance level of .561 is not significant, at df = 18.

Conclusion: Uphold the null hypothesis,

H₀ : Mean of Mortality in 20% extract = Mean of Mortality in 50% extract.

(If the t-value has a significance level lower than .05, the null hypothesis will be rejected. In this particular example, the significance level of the t-value is .561, so the null hypothesis is accepted.)