A company claims that the mean monthly residential electricity consumption in a certain region is more than 860 kilowatt-hours (kWh). You want to test this claim. You find that a random sample of 60 residential customers has a mean monthly consumption of 900 kWh. Assume the population standard deviation is 125 kWh. At x = 0.01, can you support the claim? Complete parts (a) through (e).

For each problem, select the best response. (a) The scores of adults on an IQ test is approximately Normal with mean 100 and standard deviation 15. Corinne scores 118 on such test. Her z-score is about O A. 0.67 OB. 1.2 O C. 7.87 OD. 18 O E. None of the above. (b) A researcher wishes to determine whether the rate of water flow (in liters per second) over an experimental soil bed can be used to predict the amount of soil washed away (in kilograms). In this study, the explanatory variable is the O A. size of the soil bed. O B. rate of water flow. OC. amount of eroded soil. O D. depth of the soil bed. O E. None of the above. (c) Smokers don't live as long (on the average) as nonsmokers, and heavy smokers don't live as long as light smokers. You regress the age at death of a group of male smokers on the number of packs per day they smoked. The slope of your regression line A. will be greater than zero. OB. will be less than zero. OC. must be between 1 and 1. D. can't tell without seeing…

A​ person's body mass index​ (BMI) is computed by dividing the weight​ (kg) by the square of height​ (m). The accompanying table contains the BMI statistics for random samples of males and females. Assume that the two samples are independent simple random samples selected from normally distributed​populations, and do not assume that the population standard deviations are equal. Let population 1 be females.   Female​ BMI: n=69 x=29.14 s=7.41 Male​ BMI: n=79 x=28.18 s=5.24   The test statistic is   The​ P-value is     Construct a confidence interval appropriate for testing the claim in part​ (a).   The ___​% confidence interval estimate is ___<μ1−μ2<___.

Calcium levels in people are normally distributed with a mean of 9.7 mgdL and a standard deviation of 0.5 mgdL . Individuals with calcium levels in the bottom 10% of the population are considered to have low calcium levels. Find the calcium level that is the borderline between low calcium levels and those not considered low. Carry your intermediate computations to at least four decimal places. Round your answer to one decimal place.

Please solve only only the last question.

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Suppose the average life of kiwi phones is 4.66 years with standard deviation 1.05 years. Let X represent the average lif of 40 r/s kiwi phones. Find P( x > 5)

The Z-score tells you the number of standard deviations away from the mean (and in what direction) a data value is. The formula: Z = *- can be used to find the Z-score for a single member of the population. Notice X - μ tells you the signed distance the data value (X) is from the mean. When you divide that by the size of each chunk (the standard deviation) you are measuring the distance in units of the size of the standard deviations (how many standard deviations fit in the distance between the data value and the mean) - which gives you the Z-score. The formula X = μ+Z.o can be used to find the value in the population when given the Z-score (signed number of standard deviations). Notice that Z. tells you how far from the mean the data value is (since Z is the number of standard deviations and is the size of each standard deviation the product tells the total distance). So adding the distance from the mean to the mean gives the location along the number line for the data value. A…