Question

(1 point) Ten randomly selected people took an IQ test A, and next day they took a very similar IQ test B. Their scores are shown in the table below. Person! A | B | C | D |EFGH | 1 . J Test A 111 122 107 101 89 73 83 11793 100 Test B 116 124 110 10394 7382 11493 100 1. Use a 0.05 significance level to test the claim that people do better on the second test than they do on the first. The test statistic is The critical vaue is Is there sufficient evidence to support the claim that people do better on the second test? A. No B. Yes 2. Construct a 95% confidence interval for the population mean of all differences, Test A-Test B.

Answer 1

The statistical software output for this problem is:

Paired T hypothesis test:
μ_D = μ₁ - μ₂ : Mean of the difference between Test A and Test B
H₀ : μ_D = 0
H_A : μ_D < 0
Hypothesis test results:

Difference	Mean	Std. Err.	DF	T-Stat	P-value
Test A - Test B	-1.3	0.81717671	9	-1.5908432	0.0731

95% confidence interval results:

Difference	Mean	Std. Err.	DF	L. Limit	U. Limit
Test A - Test B	-1.3	0.81717671	9	-3.1485821	0.54858214

Hence,

1. Test statistic = -1.5908

Critical value = -1.8331

No

2. 95% confidence interval:

-3.1486 < $\mu$ < 0.5486