IQ scores form a normal distribution with u=100 and σ=15. Individuals with IQs between 90 and 110 are classified as average. What proportion of the population is average?

Suppose that you are using independent samples to compare two population proportions. Fill in the blanks. a. The mean of all possible differences between the two sample proportions equals the_______.b. For large samples, the possible differences between the two samplel proportions have approximately a_________distribution.

The instructor takes a random sample of size from the population data and obtains the following sample data:                   x 405 385 495 385 555 470   8 The sample standard deviation is, a 69.17     b 66.51     c 63.14     d 61.49

Need help with this one in part D.

one z-score unit is equivalent to ______ of the distribution.  a. the variance b. the range c. the standard deviation d. the mean e. the correlation coefficient

Refer to the data set in the accompanying table. Assume that the paired sample data is a simple random sample and the differences have a distribution that is approximately normal. Use a significance level of 0.05 to test for a difference between the weights of discarded paper (in pounds) and weights of discarded plastic (in pounds). E Click the icon to view the data. In this example, Hg is the mean value of the differences d for the population of all pairs of data, where each individual difference d is defined as the weight of discarded paper minus the weight of discarded plastic for a household. What are the null and alternative hypotheses for the hypothesis test? O A. Ho: Ha = 0 H,: Ha #0 O B. Ho: Ha #0 H1: Hd =0 O C. Ho: Ha #0 O D. Ho: Ha = 0 H1: Hd 0

Fill in the blank. If a sample size is less than the sample size must come from a population having a normal distribution in order to follow normal distribution calculations. O A. 100 В. 40 OC. 50 D. 30 O O O O

Refer to the data set in the accompanying table. Assume that the paired sample data is a simple random sample and the differences have a distribution that is approximately normal. Use a significance level of 0.10 to test for a difference between the weights of discarded paper (in pounds) and weights of discarded plastic (in pounds). Click the icon to view the data In this example, Hg is the mean value of the differences d for the population of all pairs of data, where each individual difference d is defined as the weight of discarded paper minus the weight of discarded plastic for a household. What are the null and alternative hypotheses for the hypothesis test? O A. H9: Ha =0 H1: Ha 0

Select all true statements below (Multiple or none can be true). With a large, representative sample, the histogram of the sample data will follow the normal curve closely. If two lists of numbers have exactly the same average of 50 and SD of 10, then the percentage of entries between 40 and 60 must be exactly the same for both lists. Half of a list of numbers is always below its average. The median and average of a list of numbers are not necessarily close together.

In a normal curve, the percentage of the scores between one and two standard deviations above the mean is approximately __________.   Select one: a. 14% b. 50% c. It is impossible to tell. d. 2% Clear my choice