Hypothesis is always based on historical information

• 88
• 94% (362) 340 out of 362 people found this document helpful

This preview shows page 33 - 36 out of 88 pages.

hypothesis is always based on historical information. μ≥\$2,700μ≥\$2,700 The null hypothesis is the opposite of the hypothesis you are trying to substantiate. The owner wants to test for an increase. This answer would be correct if the owner wanted to test for a decrease. μ≤\$2,700μ≤\$2,700 correct The null hypothesis is the opposite of the hypothesis you are trying to substantiate. Since the owner wants to test for an increase, the null hypothesis is μ≤\$2,700μ≤\$2,700. Remember that the null hypothesis is always based on historical information. μ=\$2,700μ=\$2,700 The null hypothesis is the opposite of the hypothesis you are trying to substantiate. The owner wants to test for an increase. This answer would be correct if the owner wanted to test for a change in either direction. 4) The owner of a local health food store recently started a new ad campaign to attract more business and wants to test whether average daily sales have increased. Historically average daily sales were approximately \$2,700. After the ad campaign, the owner took another random sample of forty-five days and found that average daily sales were \$2,984 with a standard deviation of approximately \$585. Calculate the upper bound of the 95% range of likely sample means for this one-sided hypothesis test using the CONFIDENCE.NORM function.
a 5% rejection region on the left side of the normal distribution and a 5% rejection region on the right side. Thus, the upper bound for a two-sided test with alpha=0.1 will be the same as the upper bound on a one-sided test with alpha=0.05. The margin of error is CONFIDENCE.NORM(alpha, standard_dev, size)= CONFIDENCE.NORM(0.1,C3,C4)=CONFIDENCE.NORM(0.1,585,45)=\$143. 44. The upper bound of the 95% range of likely sample means for this one-sided hypothesis test is the population mean plus the margin of error, which is approximately \$2,700+\$143.44=\$2,843.44.
5) Recall that the owner of a local health food store recently started a new ad campaign to attract more business and wants to know if average daily sales have increased. Historically average daily sales were approximately \$2,700. The upper bound of the 95% range of likely sample means for this one-sided test is approximately \$2,843.44. If the owner took a random sample of forty-five days and found that daily average sales were now \$2,984, what can she conclude at the 95% confidence level?
• • • 