Amobile phone company uses the formula c = 10t + 20m to calculate the total cost of a bill. c is the total cost of the bill in pence. t is the number of text messages. m is the number of minutes of call time. calculate the total cost for 150 texts and 50 minutes of call time.

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?