4173 Dentists' use Of laughing gas According to the American Dental Association; 60% Of all dentists use nitrous oxide in their practice. If x equals the numbe...

Dentist Visits. The National Center for Health Statistics publishes information about visits to the dentist in National Health Interview Survey. The following table provides a joint probability distribution for the length of time (in years) since last visit to a dentist or other dental health professional, by age, for U.S. adults.
For a U.S. adult selected at random, determine the following probabilities and interpret your results in terms of percentages.
a. $P\left(T_{1}\right)$
b. $P\left(\text { not } A_{2}\right)$
c. $P\left(A_{4} \& T_{5}\right)$
d. $P\left(T_{4} | A_{1}\right)$
e. $P\left(A_{1} | T_{4}\right)$

And question number 29 that something is normally distributed with me and started division equal to signal over a square root of an does. That school is a value decreased by the ME divided by the Standard Division, which is equal to X minus mu over signal over the square root of them, which is equal to three 0.7 81 minus 3.796 over 4.445 over square Root of 32 is equal to negative one point 89. The second value was it scores equal to 3.811 minus 3.796. Mhm 4.0, 45 boy mhm square root off 32. It's equal to positive one point 89 to determine the correspondent Probability. Using table for P. Probability off ST Point $781. Who is less than X? This, then $3.811 Equal to Probability office Is that that Suzanne at some point 89 minus the probability of that place that negative one 0.89 is equal tool four point 9706 minus. Oh, boy Or 294 is equal to four point 24. Well, which is equal to one 94.12. Person that the answer for this question. Thank you.

So this question were given exa normally distributed random variable with mean zero and standard diminishment .75 and we're asked to find the probability is indicated, so he's driven to transform X into our standard normal random variable x minus mean over standard deviation. We're going to apply this transformation to X. So part day we basically have probably TZ is between -5.36 95.0933. Now we know, call it easy, less than 5.0933 is one. Probably easy, less than -5.360. So the probability here is one. Our theme for asked for the probability that looks is more than 4.11, which is the same as probably to Z. more than 5.48, That is 1- authorities, Z And minus the probability of c less than 5.4 ft. That here is zero Less than frequent, courageous one. So the answer here is zero.

In question number 30 but something mean is normally distributed to his mean I'm central diffusion. The city school is the value between you two by the means by the by the standard division. So we have that X is that is equal to X minus mu Oversee. My ovary squared into them is equal to 4.128 minus 400. Then for going to 117. Mhm opening all 49 boy over a square root off 38. He's just like you. Some point 13 and the other is that you were. Their school is equal to 4.133 minus 4.117. Boy, I'll bring all 39 for sporting off 13 is equal to 3.27 Toronto correspondent from about using three. Before the probability, could it be whole point $128? This the X with exclusive them $4.143 is equal to it. The world believe you, he said. Less than that's right. Point 27. Why was off the was down 1.38. Is he a great tool. 4.9000 of 995 minus 4.9000 1. 162 is equal to 2.30 street person can That defined an answer. Thank you.

And this question we are given to probabilities And we're asked to find the value that use the probability shown where access a normally distributed random variable mean 54 standard deviation 12. So we're going to use the same areas here in our conversion. So we're basically taking quality easy less than the stars equals two point goal in nine. And if we look at our table we get a value of Z star if he calls to minus 1.34 so X star, it's basically mu plus Z sigma, which gives us 37.92 458 would be for a given product X more than Next door's of poverty X. Less than X star is basically one minus this, which is 0.35 The value that's closest in RZ table This .3483 and RZ star values -199 And converting that to our extra value. Using this formula, we get 39.3 true.