Average cost is calculated in the following way
Step-by-step explanation:
Given that XO Group Inc. conducted a survey of 13,000 brides and grooms married in the United States and found that the average cost of a wedding is $29,858
X is N(29,858, 5600)
Or Z=x-29158/5600 is N*(0,1)
We can use std normal distribution table to get the probabilities
a) The probability that a wedding costs less than $20,000 (to 4 decimals)
P(X<20000)
=0.039174
=0.0392
b) the probability that a wedding costs between $20,000 and $30,000
=0.5101-0.0392
=0.4709
c) For a wedding to be among the 5% most expensive, how much would it have to cost (to the nearest whole number)
=29858+1.645*5600
=38083