level of nitrogen oxides (NOX) in the exhaust of a particular car model varies with mean 0.9 grams per mile and standard deviation 0.2 grams per mile. (a) What sample size is needed so that the standard deviation of the sampling distribution is 0.01 grams per mile? Hint: You already have an equation that gives a relationship between the population standard deviation, the sampling distribution's standard deviation, and the sample size. Do a little algebra to solve that equation for the sample size. ANSWER: (b) If a smaller sample is considered, the standard deviation for ?¯ would be . (NOTE: Enter ''SMALLER'',''

The frequency distribution was obtained using a class width of 0.5 for data on cigarette tax rates. Use the frequency distribution to approximate the population mean and population standard deviation. Compare these results to the actual mean μ=​$1.524 and standard deviation σ=​$0.968.

QUESTION 8 When purchasing bulk orders ofbatteries, a toy manufacturer uses this acceptance-sampling plan: Randomly select and test 49 batteries and determine whether each is within specifications. The entire shipment is accepted if af most 3 batteries do not meet specifications. A shipment contains 7000 batteries, and 1% of them do not meet specifications. What is the probability that this whole shipment will beaccepted? Will almost all such shipments be accepted, or will many be rejected? Round to four decimal places. 0.9485 B. 0.9514 C.0.9445 D.0.9985 QUESTION 9 Assume that adults have lQ scores that are normally distributed with a mean of mu = 105 and a standard deviation sigma15. Find the probability that a randomly selected adult has an IQ between 85 and 125 and type an integer or decimal rounded to four decimal places. Make sure to use the positive or negative z score charts attached, in the eBook on MSL, or in a hardcopy of the textbook Save All An Click Save and Submit to save…

Please help me understand the problem. Is the given standard deviations 6, and 7? I know I need to use the unit normal table, and shade the curve. But how? Thanks.