You need to define your question better. X by itself is usually just
the probability of one sample. The term X with a bar on top of it is often
used to mean the distribution of the sample mean. You must want the distribution of the sample
mean, but you did not say so.
Do you want the probability that the sample mean is 94 < x< 94.5
P( 94< X_bar< 94.5) = P(X<94.5) - P(X< 94)
sigma_sample_mean = Sigma_population/sqrt(N)= 10/sqrt(4) = 10/2 =5
P(X_bar< 94.5) = P( Z < (x-mean)/ sigma_sample_mean)
P(X_bar< 94.5) = P(Z< (94.5 -103)/ 5 )= P(Z< (-7.5/5) ) = P(Z< -1.5)
Using this online table:
https://www.stat.tamu.edu/~lzhou/stat302/standardn...
P(X_bar< 94.5) = P(Z< -1.5) = .06681
P(X_bar< 94) = P( Z< (94-103)/5) = P( Z < -8/5)
P(X_bar< 94) = P(Z < -1.6) = .05480
P( 94< X_bar< 94.5) = +0.06681-0.05480 = 0.01201
=== answer
P(94< X_bar < 94.5 ) = 0.01201
If you didn't want the distribution of the sample mean, you would need to define
what you want. For example, the probability that 2 out of the 4 samples are in this
region or the probability that 3 of 4 samples are in this region.
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Answers & Comments
You need to define your question better. X by itself is usually just
the probability of one sample. The term X with a bar on top of it is often
used to mean the distribution of the sample mean. You must want the distribution of the sample
mean, but you did not say so.
Do you want the probability that the sample mean is 94 < x< 94.5
P( 94< X_bar< 94.5) = P(X<94.5) - P(X< 94)
sigma_sample_mean = Sigma_population/sqrt(N)= 10/sqrt(4) = 10/2 =5
P(X_bar< 94.5) = P( Z < (x-mean)/ sigma_sample_mean)
P(X_bar< 94.5) = P(Z< (94.5 -103)/ 5 )= P(Z< (-7.5/5) ) = P(Z< -1.5)
Using this online table:
https://www.stat.tamu.edu/~lzhou/stat302/standardn...
P(X_bar< 94.5) = P(Z< -1.5) = .06681
P(X_bar< 94) = P( Z< (94-103)/5) = P( Z < -8/5)
P(X_bar< 94) = P(Z < -1.6) = .05480
P( 94< X_bar< 94.5) = P(X<94.5) - P(X< 94)
P( 94< X_bar< 94.5) = +0.06681-0.05480 = 0.01201
=== answer
P(94< X_bar < 94.5 ) = 0.01201
If you didn't want the distribution of the sample mean, you would need to define
what you want. For example, the probability that 2 out of the 4 samples are in this
region or the probability that 3 of 4 samples are in this region.