Answer:
<em>The container can hold 280 liters of water.</em>
Step-by-step explanation:
<u>Proportions</u>
The water originally fills 1/8 of a container. Then 35 lt of water are poured into the container and now it's 1/4 full.
If we subtract the final portion of the tank minus the original portion of the container, we obtain the portion that was poured into.
If 35 liters of water is 1/8 of the tank, then it can hold 35*8 = 280 liters.
The container can hold 280 liters of water.
Answer:
Assuming a significance level of we have that the p value is lower than this significance level so then we can conclude that the mean for checkout time is significantly less for people who use the self-service lane
Step-by-step explanation:
Data given
Our notation on this case :
represent the sample size for people who used a self service
represent the sample size for people who used a cashier
represent the sample mean for people who used a self service
represent the sample mean people who used a cashier
represent the sample standard deviation for people who used a self service
represent the sample standard deviation for people who used a cashier
Assumptions
When we have two independent samples from two normal distributions with equal variances we are assuming that
The statistic is given by:
And t follows a t distribution with degrees of freedom and the pooled variance
is given by this formula:
System of hypothesis
Null hypothesis:
Alternative hypothesis:
This system is equivalent to:
Null hypothesis:
Alternative hypothesis:
We can find the pooled variance:
And the deviation would be just the square root of the variance:
The statistic is given by:
The degrees of freedom are given by:
And now we can calculate the p value with:
Assuming a significance level of we have that the p value is lower than this significance level so then we can conclude that the mean for checkout time is significantly less for people who use the self-service lane