Question

In 1998, as an advertising campaign, the Nabisco Company announced a “1000 Chips Challenge,” claiming that every 18-ounce bag of their Chips Ahoy cookies contained at least 1000 chocolate chips. Dedicated Statistics students at the Air Force Academy (no kidding) purchased some randomly selected bags of cookies, and counted the chocolate chips. Some of their data are given below. (Chance, 12, no. 1[1999])

1219   1214   1087   1200   1419   1121   1325   1345

1244   1258   1356   1132   1191   1270   1295   1135

a) Write appropriate hypotheses.

b) Are the necessary assumptions to make inferences satisfied? Hint: draw a picture

c) State the sample mean, standard error, and p-value.

d) State an appropriate conclusion.

e) What do you think of the company’s claim?

Answer 1

a) Appropriate Hypotheses:

(Since the Null is set up for plausible rejection)

b) Assumptions:

• The sample is from a continuous population
• The sample is a simple random sample drawn from the population
• The variances are homogeneous
• The data, when plotted, results in a normal distribution, bell-shaped distribution curve.

c)

Under H₀, the test statistic follows t_n-1 distribution.

(I have used =TDIST(10.1053,15,1) function in Excel to find the p-value)

d) Conclusion:

Since the p-value<0.05, we reject the Null hypothesis and conclude that

e)

The Company's claim that every 18-ounce bag of their Chips Ahoy cookies contained at least 1000 chocolate chips holds true based on the given data.