The speeds of vehicles traveling on a highway are normally distributed with an unknown population mean and standard deviation. If a random sample of 38 vehicles is taken to estimate the mean vehicle speed, what t-score should be used to find a 99% confidence interval estimate for the population mean

The t-score of 2.715 should be used

Step-by-step explanation:

Degrees of freedom ==> n - 1 ==> 38 - 1 ==> 37

to find 99% confidence interval,  Hence,

Find t0.005 in front of 37 degrees of freedom,

Therefore the answer is, t-score = 2.715

option a, c,d are correct.

step-by-step explanation:

from the given figure, it is given that z is equidistant from the sides of the triangle rst, then from triangle tzb and triangle szb, we have

tz=sz(given)

bz=zb(common)

therefore, by rhs rule,δtzb ≅δszb

by cpctc, sz≅tz

also, from δctz and δasz,

tz=sz(given)

∠tcz=∠saz(90°)

by rhs rule, δctz ≅ δasz, therefore by cpctc, ∠ctz≅∠asz

also,from δasz and δzsb,

zs=sz(common)

∠zbs=∠saz=90°

by rhs rule, δasz ≅δzsb, therefore, by cpctc, ∠asz≅∠zsb

hence, option a, c,d are correct.