Question

A study obtained data on the amount of time 32 randomly selected young adults spent on their cell phones pre-pandemic and then during the lockdown phase of the pandemic. The investigator is interested in determining whether there is evidence that the amount of time young adults spent on their cell phone during the lockdown increased when compared to pre-pandemic times. Let
L=
time spent on phone during lockdown;
P=
time spent on phone prepandemic time; and
d=L−P
The correct null and alternative hypotheses are:
H 0
​
:μ d
​
=0
H a
​
:μ d
​

=0
H 0
​
:μ d
​
=0
H a
​
:μ d
​
<0
H 0
​
:μ L
​
−μ P
​
=0
H a
​
:μ L
​
−μ P
​

=0
H 0
​
:μ d
​
=0
H a
​
:μ d
​
>0
H 0
​
:μ L
​
−μ P
​
=0
H a
​
:μ L
​
−μ P
​
<0
H 0
​
:μ L
​
−μ P
​
=0
H a
​
:μ L
​
−μ P
​
>0

Answer 1

The Null hypothesis and alternative hypothesis for the given sample of cell phone spent time data of 32 randomly selected adults during lockdown and pre-pandemic times are,

H₀ : μd = 0

Hₐ : μd > 0

So, Correct option is option (d).

We have given that

A study obtained time data of 32 randomly selected young adults spent on their cell phones pre-pandemic and then during the lockdown phase of the pandemic. let us consider

L --> time spent on cell phone by adults during lockdown

P --> time spent on cell phone by adults at prepandemic time

and d = L- P

we want to perform a hypothesis testing on this sample .

The samples are dependent because same adults are being sampled before and after the lockdown.

Also, we need to test if mean time after is higher than mean time before so this is a right tailed test. Hence,

The correct hypotheses will be:

H₀ : μd= 0

Hₐ : μd> 0

Option D is correct.

To learn more about Hypothesis testing , refer:

https://brainly.com/question/4232174

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