IS THE STATED WEIGHT OF CHIPS
ON A FRITO-LAY SNACK SIZE BAG
ACCURATE
By-Shelley Henderson
Autumn Olsen
Brantley Shattuck
Matt Breyman
BACKGROUND INFORMATION
• For many years we have felt that we were not getting the
amount of chips that was stated on the on the Frito Lay snack
size bag of chips. After careful deliberation we decided that this
would be a very important statistical study to undertake to
benefit not only ourselves but all of humanity. We used
convenience sampling but felt that it was random enough
because our sample size was large.
THE RESEARCH QUESTION
• Is the stated weight of chips on a Frito-Lay snack size bag of
chips accurate?
• Our population was all snack sized Frito-Lay bags of chips
• Our sample size was 72 individual snack size bags
DATA COLLECTION
• We went to Broulims, Walmart, and Albertsons and bought 24 bags at
each store.
• We then used a digital scale and weighed the contents of each of the
72 bags to determine the actual weight of the chips in each bag.
• We performed a one sample T test with a level of significance of
a=0.05
• Null: The actual weight of the chips in the Frito Lay snack sized chip
bags is equal to 1 ounce.
• Alternative: The actual weight of the chips in the Frito Lay snack
sized chip bags is not equal to 1 ounce.
DATA COLLECTION V. 1.2
Frito Lay Study
Bags of Chips
35
30
25
20
15
10
5
0
0.88
0.9
0.92
0.94
0.96
0.98
1
Weight of Chips
(ounces)
1.02
1.04
1.06
1.08
1.1
DESCRIPTIVE STATISTICS
• Mean- 1.009 oz
• Standard deviation- .031 oz
• Range- .19 oz
• Median- 1.02 oz
• Mode- 1.02 oz
• Minimum weight was .90 oz
• Maximum weight was 1.09 oz
INFERENTIAL STATISTICS
• Null: The actual weight of the chips in the Frito Lay snack sized
chip bags is equal to 1 ounce.
• Alternative: The actual weight of the chips in the Frito Lay
snack sized chip bags is not equal to 1 ounce.
• Alpha level: .05
• Test Statistic: T=2.367
• P-value: .021
TAKE ACTION
• After conducting our test we realized that we are on average
getting .009 oz more than what is stated on the bag. Our action
would be to send a letter to Frito Lay thanking them for the extra
0.009 oz of chips that they so generously throw in to each bag
of their snack sized chips.
• We also thought it would be appropriate to post on social media
our findings to ease the fears of the community that they might
be getting short changed when it comes to their purchases of
snack sized Frito Lay chips.
CONCLUSION
• We reject the null hypothesis based on the p-value because
it is smaller than the level of significance.
• We have sufficient evidence to suggest that the actual
weight of the chips in the Frito lay snack sized ship bags is
not equal to 1 ounce.
• After conducting this test we have formulated an opinion as
to why we got the results we did. When Frito Lay bags
chips they use a relatively sensitive scale which measures
the amount of chips needed to meet the demand of the
stated weight on the bag of chips.
CONCLUSION CONTINUED
• There may have been some bias in that we did not do a truly random
sample but we felt that because of our budget constraints and the
limited amount of stores that carry snack sized Frito Lay chips we
conducted as random a test as can be reasonably expected.
• There was no trend when it came to the weight of a certain flavor of
chip. They all had a range of weights that was consistent with the
other flavors of chips.
• If we had to change one thing about how we did our test we would
have used a more sensitive scale to get a more accurate reading.
• http://www.youtube.com/watch?v=xYiASzqZFsg