Sana deals in designer handbags. She bought 5 handbags at a price of 18,000 each and sold them all at a profit
1 answer:
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Using normal distribution 
critical probability
critical value for the critical probability is CV = 1.96
standard error
margin of error = CV*SE = 1.96 * 0.5 = 0.98
95% confidence interval is between μ + 0.98 and <span>μ - 0.98, which is (19.62, 21.58)</span>
critical probability
critical value for the critical probability is CV = 1.96
standard error
margin of error = CV*SE = 1.96 * 0.5 = 0.98
95% confidence interval is between μ + 0.98 and <span>μ - 0.98, which is (19.62, 21.58)</span>
Answer:
The p-value here is 0.0061, which is very small and we have evidence that the girls' mean is higher than the boys' mean.
Step-by-step explanation:
We suppose that the two samples are independent and normally distributed with equal variances. Let be the mean number of ring tones for girls, and
the mean number of ring tones for boys.
We want to test vs
(upper-tail alternative).
The test statistic is
T =
where
.
For this case, ,
,
,
,
.
and the observed value is
t = .
We can compute the p-value as P(T > 2.6309) where T has a t distribution with 20 + 20 - 2 = 38 degrees of freedom, so, the p-value is 0.0061. Because the p-value is very small, we can reject the null hypothesis for instance, at the significance level of 0.05.