The grades on a geometry midterm at Santa Rita are roughly symmetric with u = 82 and o = 4.0. Emily scored 92 on the exam.
Find the z-score for Emily's exam grade. Round to two decimal places.

z-score for Emily's exam grade is 2.50

Step-by-step explanation:

Z score helps to determine position of any  observed data with respect to mean of data, when it is measured in terms of standard deviation.

Formula for  z score is given by

z = (data from sample - mean)/ standard deviation

Given in the problem

mean = 82

standard deviation = 4.0

sample score = 92

Z = (92-82)/4 = 10/4

Z = 2.5

z-score for Emily's exam grade is 2.50

d. 24+-0.114

step-by-step explanation:

the question requires us to calculate the approximate 95% confidence interval for the mean number of ounces of ketchup per bottle in the sample given the following statistics;

sample mean = 24

standard deviation, σ = 0.4

sample size , n = 49

the confidence interval for a population mean is calculated using the formula;

sample mean ± z-score*(σ/sqrt(n))

the z-score associated with a 95% confidence interval, from the standard normal tables, is;

1.96

substituting these values into the formula;

24 ± 1.96*(0.4/7)

= 24 ± 0.112

from the alternatives given, choice d is closest to the above expression;