Answer:
Experiment
Step-by-step explanation:
An observational study is a study where researchers simply collect data based on what is seen and heard and make inferences based on the data collected.
Whereas, Experimental studies are the ones where researchers introduce an intervention and study the effects.
Giovanna did not just collect data alone and make inferences based on the collected data, as is done during an observational study, but she studied the effects of the data that she collected by calculating the average driving duration for each route.
Hence we see that she conducted an Experimental study.
Answer:
6. x = 28 degrees
7. z = 1.6 cm
Step-by-step explanation:
6.
Notice that you can use the property that tells us that the addition of all internal angles of a triangle must give 180 degrees, then you write the following equation:
50 + 69 + (2 x +5) = 180
combine like terms:
119 + 2 x + 5 = 180
124 + 2 x = 180
subtract 124 from both sides:
2 x = 56
divide by 2 both sides:
x = 56 / 2
x = 28 degrees
Problem 7.
If the two triangles are congruent, then the side MN must equal side RS.
Since MN measure 1,8 cm, then RS must also measure 1.8 cm
and we can write the equation:
1.8 = 3 z - 3
adding 3 to both sides:
1.8 + 3 = 3 z
4.8 = 3 z
dividing both sides by 3:
z = 4.8 / 3
z = 1.6 cm
Answer:
For this case we want to test if life expectancy in country 1 is more than 10 years lower than in country 2, (alternatibe hypothesis), so then the system of hypothesis are:
Null hypothesis: 
Alternative hypothesis:
Or equivalently:
Null hypothesis: 
Alternative hypothesis:
Step-by-step explanation:
Previous concepts
A hypothesis is defined as "a speculation or theory based on insufficient evidence that lends itself to further testing and experimentation. With further testing, a hypothesis can usually be proven true or false".
The null hypothesis is defined as "a hypothesis that says there is no statistical significance between the two variables in the hypothesis. It is the hypothesis that the researcher is trying to disprove".
The alternative hypothesis is "just the inverse, or opposite, of the null hypothesis. It is the hypothesis that researcher is trying to prove".
Solution to the problem
For this case we want to test if life expectancy in country 1 is more than 10 years lower than in country 2, (alternatibe hypothesis), so then the system of hypothesis are:
Null hypothesis: 
Alternative hypothesis:
Or equivalently:
Null hypothesis: 
Alternative hypothesis: