For this assignment, you will practice applying hypothesis testing to the business decision scenarios. By using the Hypothesis Tester – Single Sample Excel file linked in the Resources, complete all of the given scenarios:
The vice-president of operations for a veterinary supply company has designed a new quality control process which she believes will significantly decrease the reject rate in the packing line for bottles of equine glucosamine from its historical level of 32 units per 1,000. She now wants to implement a pilot of this procedure and use it to see whether the data support her belief.
- What is the null hypothesis for this test?
- In the context of this scenario, what would be the consequences of making a Type I error?
- In the context of this scenario, what would be the consequences of making a Type II error?
Playbill Magazine had reported that the mean annual household income of its readers is $119,155. The most recent random sample of 80 households taken from its subscription list had a mean annual household income of $124,450. Past studies have pointed out that the standard deviation of household income is $30,000. Based on this information, can Playbill's executives conclude that there has been a significant shift in the average annual income of its readers? (Use alpha = .05).
To complete this scenario, use the Mall of Elbonia Interview Results (Elbonia Labled below).
One hundred customers at the Mall of Elbonia (MoE) were given a short interview as they concluded their shopping trips. Observe the resulting data in the Mall of Elbonia Interview Results (Elbonia Labled below). For each customer (by row), the spreadsheet contains data on:
- The customer's gender.
- How long the customer spent in the mall.
- How much he or she spent on food and clothing purchases.
- The customer's rating of the mall's friendliness and attractiveness.
MoE's concessions manager believes the average amount that mall customers spend on food throughout a visit has increased over the historical average of $18.75, due to the opening of some new upscale restaurants in the mall. Use the data in the file to test his hypothesis (Hypothesis Calculators Labled below).
- What is the null hypothesis?
- Would you reject it at alpha = .05?
In the past, management at Mall of Elbonia has found that their clientele was around 55% women and 45% men. Though, the new director of marketing believes that the ratio might be moving away from that traditional figure to one that is not so skewed towards women. Do the data in the sample represented in the Excel file support his contention at the .05 level of significance?