The following are measurements of the air velocity and evaporation coefficient of burning fuel droplets in an impulse engine. Fit a straight line to these data by the method of least squares, and use it to estimate the evaporation coefficient of a droplet when the air velocity is 190 cm/s correct to two decimal places.

The following are the numbers of minutes it took 10 mechanics to assemble a piece of machinery in the morning, x, and in the late afternoon, y. Calculate r correct to three decimal places.

Which of the following assertions are more accurate?

The following are measurements of the air velocity and evaporation coefficient of burning fuel droplets in an impulse engine. Fit a straight line to these data by the method of least squares, and use it to estimate the evaporation coefficient of a droplet when the air velocity is 190 cm/s correct to two decimal places.

The lapping process which is used to grind certain silicon wafers to the proper thickness is acceptable only if σ, the population standard deviation of the thickness of dice cut from the wafers, is at most 0.50 mil. Use the 0.05 level of significance to test the null hypothesis σ = 0.50 against the alternative hypothesis σ >0.50, if the thicknesses of 15 dice cut from such wafers have a standard deviation of 0.64 mil. Calculate the test statistic correct to two decimal places.

The following are the numbers of minutes it took 10 mechanics to assemble a piece of machinery in the morning, x, and in the late afternoon, y. Calculate r correct to three decimal places.

Choose the correct example for positive correlation

A treatment plant that sends effluent into the river claims the mean suspended solids

is never above 40 mg/l. Measurements of the suspended solids in river water on n = 14 Monday mornings yield sample mean as 46 and sample standard deviation 9.4 mg/l. Based on data collected over a period of many years, it is reasonable to assume that the individual

measurements follow a normal distribution. Calculate the value of t correct to 3 decimal places.

Consider the data: 136 143 147 151 158 160

161 163 165 167 173 174

181 181 185 188 190 205. Obtain a point estimate for 

A research worker wants to determine the average time it takes a mechanic to rotate

the tires of a car, and she wants to be able to assert with 95% confidence that the

mean of her sample is off by at most 0.50 minute. If she can presume from past

experience that σ = 1.6 minutes, how large a sample will she have to take? Give your answer rounded off to the nearest integer.