Use the appropriate formula to do this problem by hand. You should ONLY use Stat Key to find the theoretical distribution value for z or t (depending on the situation you either use Z or T so figure out which is correct).  Round final endpoints to the nearest whole dollar.   In a sample of 63 people in a city who lost their job as a result of the COVID 19 pandemic the mean checking/savings account balances when their jobs were lost was $4,389 with a standard deviation of $3,970.  Construct and INTERPRET the 90% confidence interval estimate for the population mean checking/savings account balance for residents in this city who lost their job due to COVID 19.

A student who took Stat 2 last semester learns that their overall course score was at the 85th percentile. Assuming that a histogram of all the Stat 2 course scores from last semester follows the normal curve, this means that this student had a score that was how many SDs above the average score? Choose the answer that is closest. Group of answer choices 1.15 1.05 1.10 1.0      PreviousNext

Assume that adults have IQ scores that are normally distributed with a mean of 102.1 and a standard deviation 16.3. Find the first quartile Q1​, which is the IQ score separating the bottom​ 25% from the top​ 75%. (Hint: Draw a​ graph.)

This assignment is worth 1 points. The extra point will be added to your overall course grade. For example: if you receive an 88% in the course you can receive up to 1 point giving you a new score of 89%. The following rubric will be used.  0.25 point for drawing the normal distribution curve with the mean value labeled on the curve and the appropriate area shaded. 0.25 point for determining the value of the standard deviation of the sample mean.  0.5 point for finding the correct probability.   All work must be shown in order to receive any credit.  Please upload your completed assignment here.    The length of time taken on the SAT for a group of students is normally distributed with a mean of 2.5 hours and a standard deviation of 0.25 hours. A sample size of n = 60 is drawn randomly from the population. Find the probability that the sample mean is between two hours and three hours.

Need crit value, the pictured question b, and rejection region.

A manufacturer of exercise equipment wanted to collect data on the effectiveness of their equipment. A magazine article compared how long it would take men and women to burn 200 calories during light or heavy workouts on various kinds of exercise equipment. The results summarized in the accompanying table are the average times for a group of physically active young men and women whose performances were measured on a representative sample of exercise equipment. Assume normality of the population. Complete parts (a) through (c) below. Click the icon to view the data table. C a) On average, how many minutes longer than a man must a woman exercise at a light exertion rate in order to burn 200 calories? Find a 95% confidence interval. minutes (Round to one decimal place as needed.) b) Estimate the average number of minutes longer a woman must work out at a light exertion than at heavy exertion to get the same benefit. Find a 95% confidence interval. (₁) minutes (Round to one decimal place…

Assume time to failure density function (in months) of transplanted kidneys has a Weibull distribution with shape factor of 3 and scale of 6. Use R and answer the following questions (enter your answers with 3 decimal points):

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.

Consider a sample data set with the summary statistics s= 112, Q = 58, and Q, =203. %3D a. Calculate IQR. b. Calculate IQR/s. c. Is the value of IQR/s approximately equal to 1.3? What does this imply? a. IQR =

A manufacturer knows that their items have a normally distributed lifespan, with a mean of 8.4 years, and standard deviation of 2.7 years. The 7% of items with the shortest lifespan will last less than how many years? Give your answer to one decimal place. years