Question

A computer scientist is investigating the usefulness of two different design languages in improving programming tasks. Twelve expert programmers, familiar with both languages, are asked to code a standard function in both languages, and the time (in minutes) is recorded. The data follow:
Programmer Design Language 1 Design Language 2
1 17 18
2 15 14
3 21 20
4 13 11
5 18 22
6 24 21
7 15 10
8 14 13
9 21 19
10 23 24
11 13 15
12 18 20
(a) Is the assumption that the difference in coding time is normally distributed reasonable?
(b) Find a 95% confidence interval on the difference in mean coding times. Is there any indication that one design language is preferable?
(a) The assumption that the difference in coding time is normally distributed
isis not
reasonable.
(b) The 95% confidence interval is (
,
) Round your answers to 3 decimal places (e.g. 98.765).
There is no / is significant indication that one design language is preferable at a 5% significance level.

Answer 1

Answer:

Step-by-step explanation:

The  histogram shown in the attached file show that the distribution of differences is approximately normal.

So, we can assume that the distribution is normal.

.

b)

The 95% confidence level for $\mu _D=\mu_1-\mu_2$ is found

$\bar d \pm t_{0.025,11}\frac{S_D}{\sqrt{n} }$

$=0.666667 \pm 2.201\frac{(2.964436)}{\sqrt{12} } \\\\0.666667 \pm 2.201(0.85576)\\\\=0.666667+ 1.883525474=2.5502\\\\=0.666667- 1.883525474=-1.2169\\\\=(-1.2169,2.5502)$

since 0  is in the confidence interval. we do not reject the null hypothesis.

No, there is no indication of one design language is available.