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Jane randomly replies to three out of every ten messages she receives. She also chooses to sit by the pool four out of seven days each week. Assuming replying to texts and sitting by the pool are independent events, what is the probability that she replies to a text and sits by the pool? Give your answer as an exact fraction and reduce the fraction as much as possible.
Several intelligence tests follow a normal distribution with a mean of 100 and a standard deviation of 15.
a. Determine the percentage of the population that would obtain a score between 95 and 110.
b. For a population of 2,500, how many are expected to have a score above 125?
A veterinary nutritionist developed a diet for overweight dogs. The total volume of food
consumed remains the same, but one half of the dog food is replaced with a low-calorie
“filler” such as canned green beans. Six overweight dogs were randomly selected from
her practice and were put on this program. Their initial weights were recorded, and then
they were weighed again after 4 weeks. At the 0.05 level of significance can it be
concluded that the dogs lost weight?
Before 42 53 48 65 40 52
After 39 45 40 58 42 47
a. State the hypothesis and identify the claim of the researcher.
b. Find the critical value(s).
c. Compute for the mean of the differences, standard deviation of the differences
and test value.
d. Make a decision on the null hypothesis.
e. Make a decision on the claim of the researcher.
A decade-old study found that the proportion of high school seniors who felt that "getting rich" was an important personal goal was 65
%
. Suppose that we have reason to believe that this proportion has changed, and we wish to carry out a hypothesis test to see if our belief can be supported. State the null hypothesis H
and the alternative hypothesis H
1
that we would use for this test.
suppose we have two hats one has 4 red balls and 6 green balls, the other has 6 red and 4 green. we toss a fair coin, if heads, pick a random ball from the first hat, if tails from the second. What is the probability of getting a red ball.
A quality-control manager at an amusement park feels that the amount of time that people spend waiting in line to ride the roller coaster is too long. To determine if a new loading and unloading procedure is effective in reducing the wait time, she measures the amount of time (in minutes) people are waiting in line for seven days. To make a reasonable comparison, she chooses times when whether conditions are similar.
Mon Tues Wed Thurs Fri Sat Sun
2 p.m. 2 p.m. 2 p.m. 2 p.m. 2 p.m. 4 p.m. 12 noon
Wait time before, 𝑋1 12 26 20 38 57 82 57
Wait time after, 𝑋2 11 28 19 36 59 75 55
Is the new loading and unloading procedure effective in reducing the wait time at the α = 0.05 level of significance?
a. State the hypothesis and identify the claim of the researcher.
b. Find the critical value(s).
c. Compute the test value.
d. Make a decision on the null hypothesis.
e. Make a decision on the claim of the researcher.
suppose 3 companies x y z produce tvs x pproduces twice as many as x while y and z produce same number as.it is known that 2%of x,2%of y,4%of z are defected all the tvs are produced are put into 1 shop and then 1 tv is choosen at random what is the probability that the tv is defeceted.suppppose a tv choosen is defective what is the probability that this tv is produced by company x.
You have found that the correlation coefficient between two variables is negative. Is it possible to calculate the coefficient of determination? Explain.
State the assumption of ordinary least square and explain the Guass-Markov theorem.
State the assumption of ordinary least square and explain the Guass-Markov theorem
#333702 on Dec 2022