Answer: c. z = 1.35; Reject the null hypothesis
Step-by-step explanation:
Let
be the average life expectancy of its batteries.
As per given , we have
Null hypothesis : 
Alternative hypothesis : 
Since
is right-tailed and population standard deviation is also known, so we perform right-tailed z-test.
Test statistic : 
where, n= sample size
= sample mean
= Population mean
=population standard deviation
For
, we have

Critical one-tailed test value for 0.10 significance level :

Decision : Since critical z value (1.28) < test statistic (1.35), so we reject the null hypothesis .
[When critical value is less than the test statistic value , we reject the null hypothesis .]
Answer: $42.4 dollars
Step-by-step explanation: PLZ PLZ PLZ MARK BRAINLIEST
Answer:
x=-2
Step-by-step explanation:
option D is the correct option
y= 10- 2x
Now, if we take the first value of x i.e 1
then, y= 10-2(1)
= 10-2 = 8 ---------> this value matches with the given value of y
take,x =2
y=10-2(2) = 10-4 = 6--------->this value matches with the given value of y
taking, x = 3
y= 10-2(3) = 10- 6=4-------->this value matches with the given value of y
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