A)The playing life of a Sunshine radio is normally distributed with mean = 600 hours
and standard deviation = 100 hours. What is the probability that a radio selected
at random will last from 600 to 700 hours?
b)Find the area under standard normal curve to the left of z = –1.00
c) Find the area to the left of z = 1.18
d) Find the area between z = 1.00 and z = 2.70.
The following data were collected during an experiment in which 10 laboratory animals were inoculated with a pathogen. The variables are Time after inoculation (X, in minutes) and Temperature (Y, in Celsius degrees).
X, Time Minutes)
Y, Temperature (0C)
24
28
32
36
40
44
48
52
56
60
38.8
39.5
40.3
40.7
41.0
41.1
41.4
41.6
41.8
41.9
i) Draw a Scatter Diagram to show the association, if any, between these two variables (correct scale is not very important);
ii. Can you draw any conclusion/observation without doing any calculation?
Iii. Calculate the Coefficient of Correlation.
iv. Form the regression line of Y on X by calculating the estimate Intercept and Slope;
v. If the model holds, what would be the temperature for an animal, chosen at random, after 30 minutes?
QUESTION FOUR:
In the fast food example from the start of this chapter, researchers want to test whether the average number of fast food meals eaten per week by modern families is larger than it was in the 1990s, when it was 3.5. Suppose that they know the population standard deviation is σ = 0.6, the sample size is 100, and the sample mean was x = 7.3