The number of cars sold annually by used car salespeople is normally distributed with a standard deviation of 16. a random sample of 310 salespeople was taken and the mean number of cars sold annually was found to be 66. find the 90% confidence interval estimate of the population mean. note: for each confidence interval, enter your answer in the form (lcl, ucl). you must include the parentheses and the comma between the confidence limits.

The 90% confidence interval is (64.0101, 68.9899).

Step-by-step explanation:

Our sample size is 310.

The first step to solve this problem is finding our degrees of freedom, that is, the sample size subtracted by 1. So

.

Then, we need to subtract one by the confidence level and divide by 2. So:

Now, we need our answers from both steps above to find a value T in the t-distribution table. So, with 309 and 0.05 in the two-sided t-distribution table, we have

Now, we find the standard deviation of the sample. This is the division of the standard deviation by the square root of the sample size. So

Now, we multiply T and s

Then

LCL is the mean subtracted by M. So:

UCL is the mean added to M. So:

The 90% confidence interval is (64.0101, 68.9899).

whatare you sayig

step-by-step explanation:

answer: the sun

explanation:

water cycle describes the evaporation of water from earth's surface, formation of clouds and precipitation water back onto the surface of earth. seventy percent of the earth is covered with water in the form of seas and oceans. the heat of the sun causes the evaporation of water from the surface of the ocean. the water vapors rise and condense to form water droplets. the collection of these water droplets form clouds which rain down again.

the evaporation of the oceans surface water as part of the water cycle is caused by the sun