Answer:
The researcher can retain the null hypothesis that the average age (in weeks) at which babies begin to crawl is not significantly different from 30 as the value 30 weeks lies within the range of values that the true average age (in weeks) at which babies begin to crawl can take on.
Explanation:
The null hypothesis plays the devil's advocate and is always about the absence of significant difference between two variables being compared.
While, the alternative hypothesis takes the other side of the hypothesis; that there is indeed a significant difference between two proportions being compared.
For this question, the null hypothesis is presented mathematically as
H₀: μ₀ = 30 weeks
And the alternative hypothesis is
Hₐ: μ₀ ≠ 30 weeks
Confidence Interval for the population mean is basically an interval of range of values where the true population mean can be found with a certain level of confidence.
With the confidence interval obtained,
29.202 < μ[age] < 31.844
The researcher can retain the null hypothesis that the average age (in weeks) at which babies begin to crawl is not significantly different from 30 as the value 30 weeks lies within the range of values that the true average age (in weeks) at which babies begin to crawl can take on.
Hope this Helps!!!