Answer:
Since the calculated value of t =-0.427 does not fall in the critical region so we accept H0 and conclude that there is enough evidence to show that mean difference in the age of onset of symptoms and age of diagnosis is 25 months .
Step-by-step explanation:
The given data is
Difference d= -24 -12 -55 -15 -30 -60 -14 -21 -48 -12 -25 -53 -61 -69 -80
∑ d= -579
∑d²= 29871
1) Let the hypotheses be
H0: ud= 25 against the claim Ha: ud ≠25
H0 : mean difference in the age of onset of symptoms and age of diagnosis is 25 months .
Ha: mean difference in the age of onset of symptoms and age of diagnosis is not 25 months.
2) The degrees of freedom = n-1= 15-1= 14
3) The significance level is 0.05
4) The test statistic is
t= d`/sd/√n
The critical region is ║t║≤ t (0.025,14) = ±2.145
d`= ∑di/n= -579/15= -38.6
Sd= 23.178 (using calculators)
Therefore
t= d`/ sd/√n
t= -38.6/ 23.178√15
t= -1.655/3.872= -0.427
5) Since the calculated value of t =-0.427 does not fall in the critical region so we accept H0 and conclude that there is enough evidence to show that mean difference in the age of onset of symptoms and age of diagnosis is 25 months .
To find the tax = $3129 × 4% = $125.16.
The final price = $3129 + $125.16 = $3254.16.
Hope this helps
Size got it right because it’s multiplied by 100
First we need to find out the time it took for the truck to reach town B.



Now, because the van left 1.5 hours earlier and reached the destination 2.5 hours before, it took 1 hour less the the truck to arrive.

which is the time it took for the van to arrive.
Now we use the speed equation again to work out speed.


= speed of van
Hope this helped :)