Answer:
Her friend gave Sheila a markdown of $15.
Step-by-step explanation:
Given;
Amount paid for 2 tickets = $90
Actual amount for each ticket = $52.50
we need to find the markdown value did her friend gave to Shelia.
Solution:
each ticket = $52.50
2 tickets = Cost of 2 tickets.
By using unitary method we get;
Cost of 2 tickets = 
Now To find the markdown we will subtract the Amount paid for 2 tickets from the actual Amount of 2 tickets.
framing in equation form we get;
Markdown 
Hence her friend gave sheila a markdown of $15.
Answer:
GF = FH
Step-by-step explanation:
GEF & FIH
EF = FI (equal)
GEF = FIH (alternate angle)
EG = HI (parallel sides equal)
GEF & FIH are congruent, under the case of (SAS)
therefore, GF = FH (corresponding angle)
Increasing the sample size by a factor of 4 or multiplying
it by 4 is equal to increasing the standard error by 1/2. Therefore, the
interval will be half as varied. This also works almost for population
averages as lengthy as the multiplier from the t-curve doesn't modify much when
increasing the sample size.