The cost of a phone is reduced by 20%. The new cost is $70.40 . What was the original price?1. $88.002.$84.003.$58.404.$56.00
1 answer:
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<h2>Answer with explanation:</h2>
By considering the given information, we have
Null hypothesis :
Alternative hypothesis :
Since the alternative hypothesis is two-tailed , so the test is a two-tailed test.
Given : Sample size : n= 20, since sample size is less than 30 so the test applied is a t-test.
;
Test statistic :
i.e.
Degree of freedom : n-1 = 20-1=19
Significance level = 0.01
For two tailed, Significance level
By using the t-distribution table, the critical value of t =
Since , the observed t-value (7.25) is greater than the critical value (2.861) .
So we reject the null hypothesis, it means we have enough evidence to support the alternative hypothesis.
We conclude that there is some significance difference between the mean score for sober women and 35.0.